UNITED STATES NUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555-0001

January 24, 2019

SECRETARY

COMMISSION VOTING RECORD

DECISION ITEM:

TITLE:

SECY-16-0142

DRAFT FINAL RULE-MITIGATION OF BEYOND-DESIGN­BASIS EVENTS (RIN 3150-AJ49)

The Commission acted on the subject paper in an Affirmation Session as recorded in the Staff Requirements Memorandum (SRM) of January 24, 2019.

This Record contains a summary of voting on this matter together with the individual vote sheets, views and comments of the Commission.

Enclosures: 1. Voting Summary 2. Commissioner Vote Sheets

cc: Chairman Svinicki Commissioner Baran Commissioner Burns Commissioner Caputo Commissioner Wright OGC EDO PDR

~!&M-~ Annette L. Vietti-Cook

Secretary of the Commission

2

VOTING SUMMARY- SECY-16-0142

RECORDED VOTES

NOT APPROVED DISAPPROVED ABSTAIN PARTICIPATING COMMENTS DATE

Chrm. Svinicki X X 10/30/18

Cmr. Baran X X 06/08/17 X X 11/30/18

Cmr. Burns X X 06/26/17 X X 12/03/18

Cmr. Caputo X X 11/08/18

Cmr. Wright X X 11/08/18

AFFIRMATION ITEM

RESPONSE SHEET

TO: Annette Vietti-Cook, Secretary

FROM: CHAIRMAN SVINICKI

SUBJECT: SECY-16-0142: DRAFT FINAL RULE-MITIGATION OF BEYOND-DESIGN-BASIS EVENTS (RIN 3150-AJ49)

Approved XX Disapproved_ Abstain_ Not Participating_

COMMENTS: Below Attached XX None

Chairman Svinicki's Comments on SECY-16-0142 Draft Final Rule - Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49)

I approve the draft final rule and notice for publication in the Federal Register, as edited in the attached version. I also approve the Backfitting and Issue Finality Assessment Supporting the Mitigation of Beyond-Design-Basis Events Final Rule, as edited in the attached version . I have approved the codification of many of the draft final rule's proposed provisions but find that the record failed to provide a sufficient basis to approve others.

In recognition of the Commission 's need to evaluate the draft final rule against the agency's backfitting regulation , in SECY-14-0046 (Enclosure 6) , the staff embraced the following approach to its preparation of the rule package before us: "[t]he staff understands that different portions of the consolidated rule making will have different backfitting justifications under 10 CFR 50.109, and accordingly portions of the consolidated rulemaking may not be supportable in accordance with the provisions of 10 CFR 50.109. The staff will also need to determine whether the consolidated rulemaking will be inconsistent with any applicable issue finality provisions in 10 CFR Part 52. As such , the staff intends to construct the consolidated rulemaking with this in mind, and enable any requirements that do not meet the backfitting or issue finality requirements to be bifurcated from the consolidated rulemaking at the final rule stage." (Emphasis added.) The revised version of the draft final rule that I support here does just that . The construction of the draft final rule in this manner by the staff facilitates the Commission 's work in excising those proposed requirements for which the staff has failed to make the requ isite showing or where the staff has not provided a backfitting analysis to substantiate the draft final rule's proposed approach.

My review of the draft final rule and the record as a whole has followed a systematic approach. I have examined each potential requirement proposed by the staff in the draft final rule , particularly those that had been previously addressed at the regulatory guidance level arising from the Mitigation Strategies and Spent Fuel Pool Instrumentation Orders, against the requirements of 10 CFR 50.109, "Backfitting ," and 1 O CFR 52.98, "Finality of combined licenses; information requests ." For items that have been addressed at the regulatory guidance level , I have considered first whether inclusion of a requirement on the subject in the final rule would be necessary to ensure that there is adequate protection of public health and safety. In many cases, I have concluded that the requirements imposed by the Orders were sufficient to provide reasonable assurance of adequate protection of public health and safety and no new information was developed through this rulemaking process or in other analyses of which I am aware to modify this conclusion . In light of this, and the inapplicability of the compliance exception , I then considered whether there would be a substantial increase in the overall protection of the public health and safety or the common defense and security that would result from including requirements in the final rule for those "guidance" items rather than continuing the practice of addressing them in the regulatory guidance as had been done for the orders. As reflected in the edited versions attached here, I found no basis to conclude that the recasting as requirements of those items currently addressed in regulatory guidance would constitute a substantial increase in the overall protection of the public health and safety or the common defense and security.

In addition, in some cases, I also concluded that the staff's proposed regulatory requirements , if imposed, could artificially constrain regulated entities from developing innovative mitigation strategies that would achieve the same outcome as, or more, effectively. Such an approach is inconsistent with the Commission's direction in SRM-SECY-11 -0124 that "[i]n order to be effective, approaches should be flexible and able to accommodate a diverse range of

circumstances and conditions. In consideration of events beyond the design basis, a regulatory approach founded on performance-based requirements will foster development of the most effective and efficient, site-specific mitigation strategies , similar to how the agency approached the approval of licensee response strategies for the 'loss of large area' event under its B.5.b program." In some cases, the draft final rule also appeared to conflate the agency's post­Fukushima site-specific regulatory processes under 10 CFR 50.54(f) with the establishment of generic regulatory requirements through rulemaking. The staff's reasoning on this was murky, at best, and - absent a much more coherent analysis than the record presented - I find no basis to support the conversion of ongoing , and effective, site-specific issue resolution into a generic requirement.

I acknowledge that this draft final rule package was developed prior to the agencywide refresher training on the backfitting regulation . Had that not been the case, perhaps the staff's proposal would have looked quite different. In any event, I am confident that no work product received by the Commission today would run so deeply afoul of the agency's own backfitting regulation .

The revised version of the draft final rule that I support here also incorporates a modification advanced by two of my colleagues, in their votes. Specifically, I agree with Commissioners Baran and Burns that there is no compelling need to hasten the removal of Order EA-06-137 and its associated post September 11 , 2001 , license conditions. I have omitted these actions from the version of the draft final rule attached here. There appears to be a clearer nexus between the removal of these duplicative requirements and the Proposed Rule on Regulatory Improvements for Facilities Transitioning to Decommissioning provided in SECY-18-0055. Because the removal of these requirements fits more cleanly within that proposed rule, it is my intention to address these provisions in my vote on SECY-18-0055.

This rule, when promulgated, represents the culmination of years of work since March of 2011. The modifications to the rule that I advance here do not detract from the central truth regarding the impact of the NRC's work since the Fukushima accident, which is this. It is not possible to visit an operating nuclear power plant in the United States today without confronting the highly visible evidence of how nuclear safety in our country has been further enhanced, in real and tangible ways, by the actions of the NRC in response to the Fukushima accident. We should be proud of the measures we imposed, and just as proud of those we assessed but did not impose, because our decisions were and are rooted in our high standards of objectivity and technical rigor. Having been with you along this journey, I am proud of our agency's response, of each of you, and grateful for your commitment to regulating with transparency and integrity.

18

[7590-01-P]

KLS Edits

NUCLEAR REGULATORY COMMISSION

10 CFR Parts 50 and 52

[Docket Nos. PRM-50-97 and PRM-50-98; NRC-2011-0189 and NRC-2014-0240]

RIN 3150-AJ49

Mitigation of Beyond-Design-Basis Events

AGENCY: Nuclear Regulatory Commission.

ACTION: Final rule.

SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is amending its regulations that

establish regulatory requirements for nuclear power reactor applicants and licensees to mitigate

beyond-design-basis events. The NRC is making generically applicable the requirements in

NRC orders for mitigation of beyond-design-basis events and for reliable spent fuel pool

instrumentation (SFPI). This rule establishes regulatory requirements for an integrated

response capability, including supporting requirements for command and control, drills, training,

and documentation of changes. This rule also establishes requirements for enhanced onsite

emergency response capabilities. Finally, this rule This rule also addresses a number of

petitions for rulemaking (PRMs) submitted to the NRC following the March 2011 Fukushima Dai-

ichi event. This rulemaking is applicable to power reactor licensees, and power reactor license

applicants, and decommissioning power reactor licensees.

2

DATES: The final rule is effective on [INSERT DATE 6030 DAYS AFTER THE DATE OF

PUBLICATION].

ADDRESSES: Please refer to Docket ID NRC-2014-0240 when contacting the NRC about the

availability of information for this action. You may obtain publicly-available information related to

this action by any of the following methods:

• Federal Rulemaking Web Site: Go to http://www.regulations.gov and search for

Docket ID NRC-2014-0240. Address questions about NRC dockets to Carol Gallagher;

telephone: 301-415-3463; e-mail: Carol.Gallagher@nrc.gov. For technical questions, contact

the individuals listed in the FOR FURTHER INFORMATION CONTACT section of this

document.

• NRC’s Agencywide Documents Access and Management System (ADAMS):

You may obtain publicly-available documents online in the ADAMS Public Documents collection

at http://www.nrc.gov/reading-rm/adams.html. To begin the search, select “ADAMS Public

Documents” and then select “Begin Web-based ADAMS Search.” For problems with ADAMS,

please contact the NRC’s Public Document Room (PDR) reference staff at 1-800-397-4209,

301-415-4737, or by e-mail to pdr.resource@nrc.gov. For the convenience of the reader,

instructions about obtaining materials referenced in this document are provided in the

“Availability of Documents” section.

• NRC’s PDR: You may examine and purchase copies of public documents at the

NRC’s PDR, Room O1-F21, One White Flint North, 11555 Rockville Pike, Rockville, Maryland

20852.

3

FOR FURTHER INFORMATION CONTACT: Timothy Reed, Office of Nuclear Reactor

Regulation, telephone: 301-415-1462, e-mail: Timothy.Reed@nrc.gov; or Eric Bowman, Office

of Nuclear Reactor Regulation, telephone: 301-415-2963, e-mail: Eric.Bowman@nrc.gov.

Both are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

SUPPLEMENTARY INFORMATION:

EXECUTIVE SUMMARY:

A. Need for the Regulatory Action

The NRC is amending its regulations to establish regulatory requirements for nuclear

power reactor applicants and licensees to mitigate beyond-design-basis events. This rule

makes NRC Order EA-12-049, “Order Modifying Licenses With Regard to Requirements for

Mitigation Strategies for Beyond-Design-Basis External Events” (Mitigation Strategies Order),

and Order EA-12-051, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool

Instrumentation” (SFPI Order), generically applicable; establishes regulatory requirements for

an integrated response capability, including supporting requirements for command and control,

drills, training, and documentation of changes; includes requirements that enhance onsite

emergency response capabilitiesdocumentation of changes; and addresses a number of PRMs

submitted to the NRC following the March 2011 Fukushima Dai-ichi event. This rule is

applicable to operating power reactor licensees, and power reactor license applicants, and

decommissioning power reactor licensees. The NRC conducted this rulemaking to amend the

regulations to reflect requirements imposed on current licensees by order and to reflect the

lessons learned from the Fukushima Dai-ichi event.

4

B. Major Provisions

Major provisions of this rule include the following amendments or additions to parts 50

and 52 of title 10 of the Code of Federal Regulations (10 CFR) that:):

• Revise the 10 CFR parts 50 and 52 “Content of applications – general

information” and “Content of applications – technical information” requirements to reflect the

additional information that would be required for applications.

• Add § 50.155, which contains beyond-design-basis mitigation requirements that

make the Mitigation Strategies and SFPI Orders generically applicable; requires an integrated

response capability for beyond-design-basis events that includes the integration of the

guidelines, strategies, and alternative approaches of § 50.155(b) with the existing emergency

operating procedures; and includes training requirements, drills or exercise requirements,

staffing and communications requirements, and the documentation of changes..

C. Costs and Benefits

The NRC prepared a regulatory analysis to determine the expected costs and benefits of

this Mitigation of Beyond-Design-Basis Events (MBDBE) final rule (MBDBE rule). The analysis

examines the costs and benefits of the rule requirements relative to the baseline case (i.e., no

action alternative, which equates to implementation of the Mitigation Strategies and SFPI

Orders without this final rule being issued). The final rule encompasses provisions that are

either completed or being implemented at this time under the Mitigation Strategies Order and

the SFPI Order and related industry initiatives.. Because the NRC uses a no action baseline to

estimate incremental costs, the total cost of the rule is estimated to be approximately $1.7

million110,000 per site followed by a recurring annual cost of $23,000.. The net present value

of these costs per site is approximately $2.0 million using a 7-percent discount rate.110,000.

5

This incremental cost is primarily attributed to licensees’ efforts to address the reevaluated

hazards as required by § 50.155(b)(2) and to a lesser degree to review the rule against the

previous implementation of the Mitigation Strategies and SFPI Orders and make any additional

changes to plant programs and procedures. The final rule is expected to result in a total one-

time cost of approximately $128 million followed by a total recurring annual cost of $17.2 million.

The net present value of these costs is approximately $1417.2 million using a 7-percent

discount rate even though the MBDBE requirements have largely been implemented prior to the

effective date of the rule under the requirements in the Mitigation Strategies Order and the SFPI

Order. The regulatory analysis includes estimates associated with the impacts incurred as a

result of licensees being required to address the reevaluated hazard information, which may

result in the need to revise mitigation strategies or implement plant modifications. Such

changes would provide a reasonable level of protection against these beyond-design-basis

events; higher levels of protection could result in licensees incurring substantially higher costs.

Based on the NRC’s assessment of the costs and benefits of the rule, the NRC has

concluded that the MBDBE rule is justified. For more information, please see the regulatory

analysis.

As required by § 50.109, “Backfitting,” and § 52.98, “Finality of combined licenses;

information requests,” a backfitting and issue finality assessment was prepared. This document

presents the reasons why the MBDBE rule provisions do not constitute backfits and are

consistent with issue finality. For certain changes that were not explicitly included in the

Mitigation Strategies Order and SFPI Order, this document also describes the NRC’s position

that they do not constitute backfits and are consistent with issue finality. Even if these

requirements had been viewed to constitute backfitting or to violate issue finality, these

requirements would be necessary for adequate protection of the public health and safety or

6

common defense and security, with one exception, do not constitute backfits and are consistent

with issue finality. The one instance of inconsistency with the issue finality provisions of § 52.98

is due to a correction to a drafting error in the former § 50.54(hh)(3), renumbered in this

rulemaking as § 50.54(hh)(2), which was intended to remove the requirements of § 50.54(hh)

upon the submittal of the certifications of permanent cessation of operation and permanent

removal of fuel from the reactor vessel. This rulemaking corrects the citation of the

requirements for these certifications from § 52.110(a)(1) to § 52.110(a) in order to include both

the certification of permanent cessation of operations and the certification of permanent removal

of fuel from the reactor vessel. Further details are provided in Section X, “Backing and Issue

Finality,” of this document.

7

Table of Contents:

I. Background

A. Fukushima Dai-ichi

B. Near-Term Task Force

C. Implementation of the Near-Term Task Force Recommendations

D. Consolidation of Regulatory Efforts

II. Opportunities for Public Involvement

III. Petitions for Rulemaking

IV. Public Comments and Changes to the Rule

V. Discussion

VI. Section-by-Section Analysis

VII. Regulatory Flexibility Certification

VIII. Availability of Regulatory Analysis

IX. Availability of Guidance

X. Backfitting and Issue Finality

XI. Cumulative Effects of Regulation

XII. Plain Writing

XIII. Environmental Assessment and Finding of No Significant Environmental Impact

XIV. Paperwork Reduction Act

XV. Congressional Review Act

XVI. Criminal Penalties

XVII. Compatibility of Agreement State Regulations

XVIII. Voluntary Consensus Standards

XIX. Availability of Documents

8

I. Background

A. Fukushima Dai-ichi

On March 11, 2011, the Great East Japan Earthquake, rated a magnitude 9.0, occurred

off the coast of Honshu Island, resulting in the automatic shutdown of 11 nuclear power plants

(NPPs) at four sites along the northeast coast of Japan, including three of six reactors at the

Fukushima Dai-ichi NPP (the three remaining plants were in outages).shutdown for

maintenance). The earthquake caused a large tsunami that is estimated to have exceeded 14

meters in height at the Fukushima Dai-ichi NPP. The earthquake and tsunami produced

widespread devastation across northeastern Japan, significantly impacting the infrastructure

and industry in the northeastern coastal areas of Japan. The earthquake and tsunami disabled

the majority of the external and internal electrical power systems at the Fukushima Dai-ichi

NPP, creating a significant challenge for operators in responding to the event. In addition, the

combination of severe events challenged the implementation of emergency plans and

procedures.

B. Near-Term Task Force

The U.S. Nuclear Regulatory Commission (NRC) Chairman’s tasking memorandum,

COMGBJ-11-0002, “NRC Actions Following the Events in Japan,” established a senior-level

task force, referred to as the “Near-Term Task Force” (NTTF)), to conduct a systematic and

methodical review of the NRC’s regulations and processes to determine if the agency should

make safety improvements to the NRC’s regulatory system in light of the events in Japan. On

July 12, 2011, the NRC staff provided the report of the NTTF (NTTF Report) to the Commission

9

as an enclosure to SECY-11-0093, “Near-Term Report and Recommendations for Agency

Actions Following the Events in Japan.” The NTTF concluded that continued U.S. plant

operation and NRC licensing activities present no imminent risk to public health and safety.

While the NTTF also concluded that the current regulatory system has served the NRC and the

public well, it found that enhancements to safety and emergency preparedness are warranted

and made 12 general recommendations for Commission consideration. In examining the

Fukushima Dai-ichi event for insights for reactors in the United States, the NTTF addressed

protecting against accidents resulting from natural phenomena, mitigating the consequences of

such accidents, and ensuring emergency preparedness. The NTTF found that the

Commission’s longstanding defense-in-depth philosophy, supported and modified as necessary

by state-of-the-art probabilistic risk assessment techniques, should continue to serve as the

primary organizing principle of its regulatory framework. The NTTF concluded that the

application of the defense-in-depth philosophy could be strengthened by including explicit

requirements for beyond-design-basis events.

C. Implementation of the Near-Term Task Force Recommendations

In response to the NTTF Report, the Commission directed the NRC staff on August 19,

2011, in Staff Requirements Memorandum (SRM)-SECY-11-0093, to engage with stakeholders

to review and assess the NTTF recommendations in a comprehensive and holistic manner and

to provide the Commission with fully-informed options and recommendations. The NRC staff

provided the Commission with recommendations for near-term action in SECY-11-0124,

“Recommended Actions To Be Taken without Delay from the Near-Term Task Force Report,”

dated September 9, 2011. The suggested near-term actions addressed several NTTF

recommendations associated with this rulemaking, including NTTF recommendations 4, 8, and

10

9.3. In SRM-SECY-11-0124, dated October 18, 2011, the Commission directed the NRC staff

to, among other things: initiate a rulemaking to address NTTF recommendation 4, station

blackout (SBO) regulatory actions, as an advance notice of proposed rulemaking (ANPR);

designate the SBO rulemaking associated with NTTF recommendation 4 as a high priority

rulemaking; craft recommendations that continue to realize the strengths of a

performance-based system as a guiding principle; and consider approaches that are flexible

and able to accommodate a diverse range of circumstances and conditions. As discussed more

fully in later portions of this noticedocument, the regulatory actions associated with NTTF

recommendation 4 evolved substantially from this early Commission direction, and included

issuance of Order EA-12-049, “Order Modifying Licenses With Regard to Requirements for

Mitigation Strategies for Beyond-Design-Basis External Events” (Mitigation Strategies Order),

that, as implemented, ultimately addressed all of NTTF recommendation 4 as well as other

recommendations.

In SECY-11-0137, “Prioritization of Recommended Actions To Be Taken in Response to

Fukushima Lessons Learned,” dated October 3, 2011, the NRC staff, based on its assessment

of the NTTF recommendations, proposed to the Commission a three-tiered prioritization for

implementing regulatory actions stemming from the NTTF recommendations. The Tier 1

recommendations were those actions having the greatest safety benefit that could be

implemented without unnecessary delay. The Tier 2 recommendations were those actions that

needed further technical assessment or critical skill sets to implement, and the Tier 3

recommendations were longer-term actions that depended on the completion of a shorter-term

action or needed additional study to support a regulatory action. On December 15, 2011, the

Commission approved the staff’s recommended prioritization in SRM-SECY-11-0137.

11

The NTTF recommendations that provide the initial regulatory impetus for this

rulemaking include: the following:

• NTTF recommendation 4: strengthen SBO mitigation capability at all operating

and new reactors for design-basis and beyond-design-basis external events;

• NTTF recommendation 7: enhance spent fuel pool (SFP) makeup capability and

instrumentation for the SFP;

• NTTF recommendation 8: strengthen and integrate onsite emergency response

capabilities such as emergency operating procedures (EOPs), severe accident management

guidelines (SAMGs), and extensive damage mitigation guidelines (EDMGs);

• NTTF recommendation 9: require that facility emergency plans address staffing,

dose assessment capability, communications, training and exercises, and equipment and

facilities for prolonged SBO, multi-unit events, or both;

• NTTF recommendation 10: pursue additional emergency protection topics

related to multi-unit events and prolonged SBO, including command and control structure and

the qualifications of decision makers; and

• NTTF recommendation 11: pursue emergency management topics related to

decision making, radiation monitoring, and public education, including the ability to deliver

equipment to the site with degraded offsite infrastructure.

In response to input received from stakeholders, the NRC accelerated the schedule

originally proposed in SECY-11-0137. On February 17, 2012, the NRC staff recommended in

SECY-12-0025, “Proposed Orders and Requests for Information in Response to Lessons

Learned From Japan’s March 11, 2011, Great Tōhoku Earthquake and Tsunami,” that the

Commission issue orders for items that warranted generic safety improvements and requests

12

for information where further consideration of the need for safety improvements would be

necessary on a site-specific basis.

To address Tier 1 NTTF recommendation 4, on March 12, 2012 the NRC issued the

Mitigation Strategies Order on March 12, 2012, requiring all U.S. nuclear power plant licensees

to have additional capability to mitigate beyond-design-basis external events through the

implementation of strategies and guidelines that enable them to cope without their permanently

installed alternating current (ac) electrical power sources for an indefinite period of time. These

strategies would provide additional capability to maintain or restore reactor core and spent fuel

cooling, as well as protect the reactor containment. This order also addressed: portions of

NTTF recommendation 9 to require that facility emergency plans address prolonged SBOs and

multi-unit events; portions of NTTF recommendation 10 to pursue additional emergency

protection topics related to multi-unit events and prolonged SBO; and portions of NTTF

recommendation 11 to pursue emergency procedure topics related to decision making, radiation

monitoring, and public education.

To address Tier 1 NTTF recommendation 7, on March 12, 2012 the NRC issued Order

EA-12-051, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation”

(SFPI Order), on March 12, 2012, requiring all U.S. nuclear power plant licensees to have a

reliable indication of the water level in associated SFPs.

To address Tier 1 NTTF recommendation 8, the NRC issued an ANPR (77 FR 23161)

on April 18, 2012 (77 FR 23161),, to engage stakeholders in rulemaking activities associated

with the methodology for the integration of onsite emergency response processes, procedures,

training and exercises.

13

The requests for information were issued under 10 CFR 50.54(f) on March 12, 2012 to

address elements of NTTF recommendation 2, concerning external hazard walkdowns and

reevaluations, and NTTF recommendation 9, concerning staffing and communications.

D. Consolidation of Regulatory Efforts

While developing the rulemakings discussed in the previous section, the NRC staff

recognized that efficiencies could be gained by consolidating the rulemaking efforts due to the

inter-relationships among the proposed changes. The NRC staff recommended to the

Commission that rulemaking activities to address NTTF recommendations 4, 7, 8, 10.2, and

11.1, as well as portions of NTTF recommendation 9, be consolidated. (See

COMSECY-13-0002, “Consolidation of Japan Lessons Learned Near-Term Task Force

Recommendations 4 and 7 Regulatory Activities,” dated January 25, 2013;

COMSECY-13-0010, “Schedule and Plans for Tier 2 Order on Emergency Preparedness for

Japan Lessons Learned,” dated March 27, 2013; and SECY-14-0046, “Fifth 6-Month Status

Update on Response to Lessons Learned From Japan’s March 11, 2011, Great Tōhoku

Earthquake and Subsequent Tsunami,” dated April 17, 2014.) Section I.C, “Implementation of

the Near-Term Task Force Recommendations,” of this noticedocument contains a more

complete discussion of the scope of NTTF recommendations addressed by the MBDBE rule.

The Commission approved these consolidations in the associated SRMs. Consequently, the

MBDBE rule combines two NRC activities for which documents have been published in the

Federal Register - Onsite Emergency Response Capabilities (RIN 3150-AJ11;

NRC-2012-0031) and Station Blackout Mitigation Strategies (RIN 3150-AJ08; NRC-2011-0299).

The MBDBE rule identification number and regulations.gov docket number are RIN 3150-AJ49

14

and NRC-2014-0240, respectively. These consolidations were intended to: meet the following

objectives:

1. Align the regulatory framework with ongoing industry implementation efforts to

produce a more coherent and understandable regulatory framework. Given the complexity of

these requirements and their associated implementation, the NRC concluded that this was an

important objective for the regulatory framework.

2. Reduce the potential for inconsistencies and complexities between the related

rulemaking actions that could occur if the efforts remained as separate rulemakings.

3. Facilitate better understanding of the requirements for both internal and external

stakeholders, and thereby lessen the impact on internal and external stakeholders who would

otherwise need to review and comment on multiple rulemakings while cross-referencing both

proposed rules and sets of guidance documents.

II. Opportunities for Public Involvement

As discussed in sectionSection I.D, “Consolidation of Regulatory Efforts,” of this

noticedocument, the MBDBE rule is a consolidation of several regulatory activities, including two

previous rulemaking efforts: the Station Blackout Mitigation Strategies rulemaking and the

Onsite Emergency Response Capabilities rulemaking. Both of these rulemaking efforts offered

extensive external stakeholder involvement opportunities, including public meetings, ANPRs

issued for public comment, and draft regulatory basis documents issued for public comment.

The major opportunities for stakeholder involvement were as follows:

1. Station Blackout ANPR (77 FR 16175; March 20, 2012);

2. Onsite Emergency Response Capabilities ANPR (77 FR 23161; April 18, 2012);

15

3. Station Blackout Mitigation Strategies draft regulatory basis and draft rule

concepts (78 FR 21275; April 10, 2013); and

4. Onsite Emergency Response Capabilities draft regulatory basis (78 FR 1154;

January 8, 2013).

The final Station Blackout Mitigation Strategies regulatory basis was issued on July 23,

2013 (78 FR 44035), and the final Onsite Emergency Response Capabilities regulatory basis,

with preliminary proposed rule language, was issued on October 25, 2013 (78 FR 63901). The

NRC described in each final regulatory basis document how it considered stakeholder feedback

in developing the respective final regulatory basis, including consideration of ANPR comments

and draft regulatory basis document comments. Section 5 of the Station Blackout Mitigation

Strategies regulatory basis document includes a discussion of stakeholder feedback used to

develop the final regulatory basis. Appendix B to the Onsite Emergency Response Capabilities

regulatory basis includes a discussion of stakeholder feedback used to develop that final

regulatory basis.

The public has had multiple opportunities to engage in these regulatory efforts. Most

noteworthy were the following:

1. Preliminary proposed rule language for Onsite Emergency Response Capabilities

made available to the public on November 15, 2013 (78 FR 68774).

2. Consolidated rulemaking proof of concept language made available to the public

on February 21, 2014.

3. Preliminary proposed rule language for MBDBE rulemaking made available to

the public on August 15, 2014.

16

4. Preliminary proposed rule language for MBDBE rulemaking made available to

the public on November 13, 2014, and December 8, 2014, to support public discussion with the

Advisory Committee on Reactor Safeguards (ACRS).

The NRC issued the MBDBE proposed rule on November 13, 2015 (80 FR 70609), for a

90-day public comment period. The comment period closed on February 11, 2016. During the

public comment period, on January 21, 2016, the NRC held a public meeting to provide external

stakeholders with a better understanding of the proposed requirements and thereby facilitate

more informed feedback. Twenty sets of comments were received in response to the proposed

rule. The NRC’s consideration of these comments is addressed in sectionSection IV, “Public

Comments and Changes to the Rule,” of this noticedocument. The NRC staff has had

numerous interactions with the ACRS, and in all cases these were public meetings, including

the following:

1. The ACRS Plant Operations and Fire Protection subcommittee met on

February 6, 2013, to discuss the Onsite Emergency Response Capabilities regulatory basis.

2. The ACRS Regulatory Policies and Practices subcommittee met on December 5,

2013, and April 23, 2013, to discuss the Station Blackout Mitigation Strategies regulatory basis.

3. The ACRS full committee met on June 5, 2013, to discuss the Station Blackout

Mitigation Strategies regulatory basis.

4. The ACRS Fukushima subcommittee met on June 23, 2014, to discuss

consolidation of Station Blackout Mitigation Strategies and Onsite Emergency Response

Capabilities rulemakings.

5. The ACRS full committee met on July 10, 2014, to discuss consolidation of

Station Blackout Mitigation Strategies and Onsite Emergency Response Capabilities

rulemakings.

17

6. The ACRS Fukushima subcommittee met on November 21, 2014, to discuss

preliminary proposed MBDBE rulemaking language.

7. The ACRS full committee met on December 4, 2014, to discuss preliminary

proposed MBDBE rulemaking language.

8. The ACRS Fukushima subcommittee met on March 19, 2015, to discuss the

proposed MBDBE rulemaking package.

9. The ACRS full committee met on April 9, 2015, to discuss the proposed MBDBE

rulemaking package.

10. The ACRS full committee met on June 10, 2015, to receive a status update on

the efforts to develop supporting guidance to implement the MBDBE rule.

11. The ACRS Fukushima subcommittee met on April 22, 2016, to receive an update

on the public comments provided on the proposed MBDBE rule.

12. The ACRS Fukushima subcommittee met on August 17, 2016, to discuss the

path forward on the substantive public comments provided on the MBDBE rule.

13. The ACRS Fukushima subcommittee met on October 19, 2016, to discuss the

final MBDBE rule guidance.

14. The ACRS Fukushima subcommittee met on November 16, 2016, to discuss the

final MBDBE rule package.

15. The ACRS full committee met on November 30, 2016, to discuss the final

MBDBE rule package.

The NRC held a public meeting on November 10, 2016, to discuss implementation

issues associated with the MBDBE final rule as required by its cumulative effects of regulation

(CER) process.

18

III. Petitions for Rulemaking

During development of this rule, the NRC gave consideration to the issues raised in six

PRMs submitted to the NRC, five from the Natural Resources Defense Council, Inc. (NRDC)

(PRM-50-97, PRM-50-98, PRM-50-100, PRM-50-101, and PRM-50-102),) and one submitted by

Mr. Thomas Popik (PRM-50-96). The NRDC petitions were dated July 26, 2011, and docketed

by the NRC on July 28, 2011. The NRC published a notice of receipt in the Federal Register on

September 20, 2011 (76 FR 58165)), for the NRDC petitions, and did not ask for public

comment at that time. The petitions filed by the NRDC use the NTTF Report as the sole basis

for the PRMs. The NTTF recommendations that the NRDC PRMs rely upon are: 4.1, 7.5, 8.4,

9.1, and 9.2. This rule addresses each of these recommendations, and therefore it resolves the

issues raised by the NRDC PRMs. Accordingly, the NRC’s issuance of the MBDBE rule

completes all planned regulatory activities for the NRDC petitions. The PRM-50-96, filed by Mr.

Popik, is still under consideration by the NRC and is not fully addressed at this time, as

discussed in greater detail below.

In PRM-50-97 (NRC-2011-0189), the NRDC requested emergency preparedness

enhancements for prolonged SBOs in the areas of communications ability, Emergency

Response Data System (ERDS) capability, training and exercises, and equipment and facilities

(NTTF recommendation 9.2). The NRC considered the issues raised in this PRM as part of the

MBDBE rulemaking. The NRC’s consideration of the issues raised in PRM-50-97 are reflected

in the provisions in § 50.155(c)(4) concerning communications, § 50.155(d) concerning training,

and § 50.155(e) concerning drills or exercises.. The NRC concludes that consideration of the

PRM issues and the underlying NTTF Report recommendations, as discussed in this

19

noticedocument, addresses PRM-50-97. This completes the NRC’s consideration of PRM-50-

97.

In PRM-50-98 (NRC-2011-0189), the NRDC requested emergency preparedness

enhancements for multi-unit events in the areas of personnel staffing, dose assessment

capability, training and exercises, and equipment and facilities (NTTF recommendation 9.1).

The NRC considered the issues raised in this PRM as part of the MBDBE rulemaking. The

NRC’s consideration of the issues raised in PRM-50-98 are reflected in the provisions in

§ 50.155(b)(51) concerning development, implementation and maintenance of strategies and

guidelines, which subsumes staffing, § 50.155(c)(4) concerning communications,and

§ 50.155(d) concerning training, and § 50.155(e) concerningwhich subsumes drills or exercises.

The NRC concludes that consideration of the PRM issues and the underlying NTTF Report

recommendations, as discussed in this noticedocument, addresses PRM-50-98. This

completes the NRC’s consideration of PRM-50-98.

In PRM-50-100, the NRDC requested enhancement of SFP makeup capability and

instrumentation for the SFP (NTTF recommendation 7.5). The NRC determined that the issues

raised in this PRM should be considered in the NRC’s rulemaking process, and the NRC

published a document in the Federal Register with this determination on July 23, 2013

(78 FR 44034). The NRC’s consideration of the issues raised in PRM-50-100 within the

MBDBE rulemaking are reflected in the provisions in § 50.155(b)(1) concerning mitigation

strategies for maintaining or restoring SFP cooling capabilities and § 50.155(fe) concerning SFP

monitoring. The NRC concludes that consideration of the PRM issues and the underlying NTTF

Report recommendations, as discussed in this notice, addressdocument, addresses

PRM-50-100. This completes the NRC’s consideration of PRM-50-100.

20

In PRM-50-101, the NRDC requested that § 50.63, “Loss of all alternating current

power,” be revised to establish a minimum coping time of 8 hours for a loss of all ac power;

establish the equipment, procedures, and training necessary to cope with an extended loss of

ac power (72 hours) for core and SFP cooling and for reactor coolant system and primary

containment integrity as needed; and establish requirements to preplan/prestage offsite

resources to support uninterrupted core and SFP cooling and reactor coolant system and

containment integrity as needed (NTTF recommendation 4.1). The NRC determined that the

issues raised in this PRM should be considered in the NRC’s rulemaking process, and the NRC

published a document in the Federal Register with this determination on March 21, 2012 (77 FR

16483). The NRC’s consideration of the issues raised in PRM-50-101 within the MBDBE

rulemaking is reflected in the provisions in § 50.155(b)(1) concerning mitigation strategies for

maintaining or restoring core cooling, containment, and SFP cooling capabilities,; § 50.155(c)

concerning equipment,; § 50.155(d) concerning training, § 50.155(e) concerning drills or

exercises,; and § 50.155(gf) concerning documentation of changes. The NRC concludes that

consideration of the PRM issues and the underlying NTTF Report recommendations, as

discussed in this noticedocument, addresses PRM-50-101. This completes the NRC’s

consideration of PRM-50-101.

In PRM-50-102, the NRDC requested more realistic, hands-on training and exercises on

SAMGs and EDMGs for licensee staff expected to implement those guideline sets and make

decisions during emergencies (NTTF recommendation 8.4). The NRC determined that the

issues raised in this PRM should be considered in the NRC’s rulemaking process, and the NRC

published a document in the Federal Register with this determination on April 27, 2012

(77 FR 25104). The NRC’s consideration of the issues raised in PRM-50-102 within the

MBDBE rulemaking are reflected in the provisions in § 50.155(d) concerning training and

21

§ 50.155(e) concerning drills or exercises.. The NRC concludes that consideration of the PRM

issues and the underlying NTTF Report recommendations, as discussed in this noticedocument,

addresses PRM-50-102. This completes the NRC’s consideration of PRM-50-102.

In PRM-50-96, Mr. Thomas Popik requested that the NRC amend its regulations to

require facilities licensed by the NRC to assure long-term cooling and unattended water makeup

of SFPs in the event of geomagnetic disturbances caused by solar storms resulting in long-term

loss of power. The NRC determined that the issues raised in this PRM should be considered in

the NRC’s rulemaking process, and the NRC published a document in the Federal Register with

this determination on December 18, 2012 (77 FR 74788). In that Federal Register document,

the NRC also closed the docket for PRM-50-96. Specifically, the NRC indicated that it would

monitor the progress of the MBDBE rule to determine whether the requirements established

therein would address, in whole or in part, the issues raised in the PRM. In this context, the

requirements in § 50.155(b)(1) and (c) and the associated regulatory guidance, address, in part,

the issues raised by the petitioner because these regulations require licensees to establish

offsite assistance to support maintenance of the key functions (including both reactor and SFP

cooling) following an extended loss of ac power, which has been postulated as a consequence

of geomagnetic disturbances.

The other issues raised in PRM-50-96 related to geomagnetic disturbances remain under

NRC consideration. The issue of geomagnetic disturbances, as it impacts transmission system

protection, is being addressed at a national level by the White House’s Office of Science and

Technology Policy (OSTP). The OSTP has been meeting with representatives from several

different Federal agencies, including the NRC, over the last several years to develop the

National Space Weather Strategy (NSWS) and the National Space Weather Action Plan

(NSWAP). On October 13, 2016, President Obama issued Executive Order 13744,

22

“Coordinating Efforts To Prepare the Nation for Space Weather Events,”” (81 FR 71573;

October 18, 2016)), requiring agencies to begin to implement the NSWAP. The Department of

Homeland Security (DHS) is the sector-specific agency with lead responsibility for nuclear

reactors, materials, and waste; therefore, the NRC is working with DHS on delineating the NRC

authorities associated with the NSWAP.

Following completion of the MBDBE rulemaking, the NRC will address PRM-50-96 giving

consideration to the NSWAP, the MBDBE rule, requirements recently established by the

Federal Energy Regulatory Commission to address geomagnetic disturbances (81 FR 67120;

September 30, 2016), and the additional comments that were submitted on this rulemaking that

further inform the consideration of geomagnetic disturbances.

IV. Public Comments and Changes to the Rule

A. Overview of Public Comments and Removal of Requirements That Would Constitute

Backfitting

During the public comment period for the MBDBE proposed rule and draft guidance, the

NRC received 20 comment submissions containing 185 individual comments. In developing the

final rule and supporting guidance, the NRC considered all the comments provided in response

to the MBDBE proposed rule and draft guidance. The detailed consideration of the public

comments is contained in a separate document that is referenced in sectionSection XIX,

“Availability of Documents,” of this noticedocument. While the NRC received many comments

that enabled it to significantly improve the MBDBE rule and its supporting statement of

considerations, this section focuses on the subset of those comments that directly resulted in

changes to the MBDBE rule requirements, or changes to the MBDBE rule supporting statement

23

of considerations. This section also discusses noteworthy feedback received in response to

specific questions in the Federal Register notice for the proposed rule and through the CER

questions.

In addition, the NRC reexamined the potential requirements that had been included in

the Proposed MBDBE Rule, particularly those that had been previously addressed at the

regulatory guidance level regarding the Mitigation Strategies and SFPI Orders, in light of the

requirements of § 50.109, “Backfitting,” and § 52.98, “Finality of combined licenses; information

requests.” For items that were addressed at the regulatory guidance level, the NRC considered

first whether inclusion of a requirement on the subject in the final rule would be necessary to

ensure that there is adequate protection of public health and safety. In each case, the NRC

concluded that the requirements imposed by the Orders were sufficient to provide reasonable

assurance of adequate protection of public health and safety and no new information was

developed with regard to the “guidance” items that would modify this conclusion. The NRC then

considered whether there would be a substantial increase in the overall protection of the public

health and safety or the common defense and security that would result from including

requirements in the final rule for those items rather than continuing the practice of addressing

them in the regulatory guidance as had been done for the orders. As discussed in the

remainder of this section, the NRC concluded in general that, while there would be some benefit

in the form of clarity as to what had been found acceptable for compliance with the orders being

made generically applicable in this rulemaking, the recharacterization of those items from

regulatory guidance to requirements would not constitute a substantial increase in the overall

protection of the public health and safety or the common defense and security.

24

The NRC also took into consideration whether the items that had been addressed in the

regulatory guidance were supporting elements to the overarching requirements for a capability

to provide protection of public health and safety or whether the items directly affect public health

and safety. For example, staffing and communications would be considered supporting

elements for the overarching requirement to develop, implement, and maintain the mitigation

strategies for beyond-design-basis external events, which contributes to the protection of public

health and safety. Because of this, the NRC concludes that a separate requirement for the

staffing and communications elements would not be needed, but could constrain an existing

licensee or an applicant for a new licensee from developing innovative mitigation strategies that

do not rely on staffing or communications. This follows the Commission’s direction in SRM-

SECY-11-0124 that “[i]n order to be effective, approaches should be flexible and able to

accommodate a diverse range of circumstances and conditions. In consideration of events

beyond the design basis, a regulatory approach founded on performance-based requirements

will foster development of the most effective and efficient, site-specific mitigation strategies,

similar to how the agency approached the approval of licensee response strategies for the ‘loss

of large area’ event under its B.5.b program.”

A discussion of the specific consideration of these items is provided in the remainder of

this section.

B. Removal of Requirements to Address Seismic and Flooding Reevaluated Hazards

The NRC received comments stating that the need for a licensee’s strategies and

guidelines to be capable of execution in the context of the reevaluated flooding and seismic

hazards should be addressed in § 50.155(b) rather than § 50.155(c)(2). The commenters noted

that addressing the effects of reevaluated hazards on the mitigation strategies in § 50.155(b)

25

rather than § 50.155(c)(2) provides greater flexibility regarding how a licensee can address the

hazard effects through changes to mitigation strategies and guidelines, to includeincluding

changes to equipment protection. Additionally, commenters indicated that the regulation should

allow for alternative approaches that would not necessarily address the damage state assumed

for § 50.155(b)(1),) nor necessarily assume the same success criteria, and that should also

allow for the use of risk-informed approaches.

The NRC agrees in part with this commentthese comments and concludes that including

thea requirement to address the effects of reevaluated hazards on the mitigation strategies in

§ 50.155(b), specifically new § 50.155(b)(2), improves the alignment of the regulationthe rule

would not be consistent with the supporting implementation guidance in Regulatory Guide (RG)

1.226, “Flexible Mitigation Strategies for Beyond-Design-Basis Events,” which provides§ 50.109,

“Backfitting,” (the Backfit Rule) and § 52.98, “Finality of combined licenses; information

requests,” and could unduly limit the flexibility the commenters suggested should be in the rule.

The NRC concludes that it is unnecessary to include languagemitigation strategies

under § 50.155(b)(1) originated in the MBDBE rule to allow for risk-informed approaches

because the regulation does not preclude such approaches. To clarify thisMitigation Strategies

Order and were justified as necessary to provide adequate protection of public health and safety

in light of the uncertainties associated with beyond-design-basis external events and the

possibility that extreme natural phenomena could challenge the prevention, mitigation, and

emergency preparedness defense-in-depth layers. In COMSECY-14-0037, “Integration of

Mitigating Strategies for Beyond-Design-Basis External Events and The Reevaluaton of

Flooding Hazards,” dated November 21, 2014, the supporting discussion for § 50.155(b)(2) in

section VI, “Section-by-Section Analysis,” of this notice states that risk-informed approaches, in

addition to deterministic approaches are acceptable for complying with NRC staff recognized

26

the § 50.155(b)(2) requirements. This is further supported by the supporting guidance in RG

1.226, which addressesinteraction between the development and implementation of mitigation

strategies for beyond-design-basis external events under the use of risk-informed approaches.

Mitigation Strategies Order and the reevaluation of flooding hazard levels using present-day

regulatory guidance and methodologies from flooding evaluations used for early site permits

and combined license reviews under NTTF Recommendation 2.1. To resolve this interaction, in

COMSECY-14-0037, the staff “ask[ed] the Commission to support the planned approach by

affirming that the MBDBE rulemaking needs to require mitigating strategies that are able to

address the reevaluated flooding hazards developed in response to the § 50.54(f) letters in

order to ensure reasonable assurance of adequate protection of the public health and safety.”

In its SRM dated March 30, 2015, “Staff Requirements - Integration of Mitigating Strategies for

Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards,” the

Commission did not make the affirmation as requested by the staff.

The final rule is revised to address reevaluated hazards in § 50.155(b)(2) rather than in

§ 50.155(c)(2) as proposed by the NRC or in § 50.155(b)(1) as proposed by the commenters.

The provisions (i.e., EDMGs) that were proposed as § 50.155(b)(2) are now moved to

§ 50.155(b)(3) in the MBDBE rule.

Reasonable Under paragraph (a)(3) of § 50.109, “Backfitting,” of this chapter, when the

exceptions of paragraph (a)(4) of that section do not apply, the NRC may require backfitting of a

facility when it determines, based upon an analysis as described in paragraph (c) of that

section, that there is a substantial increase in the overall protection of the public health and

safety or the common defense and security to be derived from the backfit and that the direct and

indirect costs of implementation for that facility are justified in view of the increased protection.

27

To support that analysis, the Commission directed the staff to evaluate potential changes to the

guidance for the integrated assessment of the effects of the flooding hazards on operating

reactors and to introduce more realism for the purpose of identifying potential safety

enhancements for operating reactors.

The changes to the regulatory decision-making process directed in the SRM to

COMSECY-14-0037 reflected the recognition that the present-day regulatory guidance and

methodologies are intended to identify a necessary level of protection from flooding that would

meet the principal design criterion of an application for an operating license or combined license

corresponding to Criterion 2 of 10 CFR part 50, appendix A, “General Design Criteria for

Nuclear Power Plants.” That criterion states that “[s]tructures, systems and components

important to safety shall be designed to withstand the effects of natural phenomena such as

earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to

perform their safety functions. The design bases for these structures, systems and components

shall reflect: (1) appropriate consideration of the most severe of the natural phenomena that

have been historically reported for the site and surrounding area, with sufficient margin for the

limited accuracy, quantity, and period of time in which the historical data have been

accumulated, (2) appropriate combinations of the effects of normal and accident conditions with

the effects of the natural phenomena and (3) the importance of the safety functions to be

performed.” Historically, the margin specified in this criterion has been achieved through the

incorporation of conservatisms in the analyses used to determine the flooding design bases for

power reactors rather than by the use of a minimum margin above the results of the analyses.

The existence of these conservatisms was addressed by the Commission in its direction in the

SRM to reduce any unnecessary conservatisms and identify any areas with insufficient

conservatisms. In keeping with that determination, the NRC concludes that adequate protection

28

of public health and safety does not require the operating power reactor licensees to provide

protection beyond those levels determined under Criterion 2 of appendix A to 10 CFR part 50

and that any backfitting in this area should be accomplished on an individualized basis under

the Backfit rule. The consideration of whether individual operating licenses for power reactor

licensees should be modified, suspended, or revoked is being accomplished under the NRC

efforts associated with the request for information issued under § 50.54(f) of this chapter on

March 12, 2012.

Therefore the NRC disagrees with the recommendation of these comments that the

reevaluated hazards levels be included in § 50.155(b) because that treatment would be

inconsistent with the Backfit rule and the issue finality provisions of part 52 of this chapter, but

agrees that the reevaluated hazards should not be included in § 50.155(c).

The final rule is revised to remove reference to the reevaluated hazards, allowing

licensees to address them within their mitigating strategies in a flexible and appropriate manner.

Consideration of the treatment of reevaluated hazards resulting from the March 12, 2012,

request for information issued under § 50.54(f) is nearing completion under a separate NRC

process.

C. Protection of Equipment

The NRC received comments that indicated a lack of clarity associated with the proposed

requirements for “reasonable protection.”” of the equipment in § 50.155(b)(1) from the effects of

natural phenomena. The commenters indicated that there appeared to be conflict regarding the

application of the reasonable protection requirement to portable “FLEX equipment” as defined in

NEI 12-06, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,” versus

application to installed structures systems, and components (SSCs) relied on for the response

29

to beyond-design-basis external events (i.e.,. These are typically safety-related SSCs relied on

in the initial response to a beyond-design-basis external event as well as design-basis events,

that as a result of their credited use for such events, have both beyond-design-basis and safety-

related functions).. Comments suggested that the proposed approach for “reasonable

protection” was too limiting because it appeared to restrict licensees to applying “reasonable

protection” only to equipment itself, and not allow licensees the flexibility to implement broader

changes in protection and/or changes to strategies.

The NRC agrees that the proposed requirements for reasonable protection need to be

clarified and revised to provide greater flexibility. First, the reasonable protection requirements

in the MBDBE rule are clarified in part, due to relocationremoval of the reevaluated hazards

requirements tofrom § 50.155(b)(2). Moving. Removal of the reevaluated hazards requirement

enabled the NRC to directly align the reasonable protection standard, in terms of the magnitude

of natural phenomena that must be considered, with either the current external event design

basis or the reevaluated seismic or flooding hazard (if one or both of those exceeds the current

external event design basis). Second, the MBDBE rule contains reasonable protection

requirements in § 50.155(c)(2) and (c)(3), which cross reference the corresponding

requirements in § 50.155(b)(1) and (b)(2), and enables greater flexibility for licensees to make

changes in protection and/or changes to strategies and guidelines, or event-specific

approaches.. Additionally, § 50.155(c)(2) was revised to characterize more clearlyspecifically

the effects of natural phenomena from which the equipment must be reasonably protected as

“equivalent in magnitude to the phenomena assumed for developing the design basis of the

facility” rather than “equivalent to the design basis of the facility,” as was described in the

proposed rule.

30

Section VI of this noticedocument is revised to clarify how the concept of “reasonable

protection” is applied to establishestablishes a degree of assurance that is appropriate for the

beyond-design-basis regulatory framework established through the MBDBE rule. This concept

contrasts with the application of special treatment requirements, such as environmental

qualification and quality assurance requirements, which are applied to safety-related SSCs, for

their design-basis-related functions, to achieve a high level of regulatory assurance appropriate

for design-basis requirements.

The NRC also clarifies the confusion that appears to stem from the application of the

“reasonable protection” standard to safety-related SSCs that have both design-basis and

beyond-design-basis functions. Safety-related SSCs that function initially in response to

beyond-design-basis external events have two sets of functions: safety-related functions and

beyond-design-basis functions. The NRC imposes extensive, special treatment requirements

on these SSCs for their safety-related functions for design-basis events. This framework

produces an increased level of assurance that the SSCs will perform those safety-related

functions during and/or following the design-basis events as applicable. (See “Risk-Informed

Categorization and Treatment of Structures, Systems and Components for Nuclear Power

Reactors; Final Rule,”” (69 FR 68008; November 22, 2004).)

Through this rulemaking, the NRC places fewer regulatory requirements associated with

the beyond-design-basis functions that dual-function SSCs perform to maintain or restore core

cooling, containment, and SFP cooling capabilities, as compared to their safety-related, design-

basis functions. The reevaluated hazards are not design-basis external events, and therefore

the regulatory approach for addressing the reevaluated hazard information in the MBDBE rule is

fundamentally different from the regulatory approach used to address design-basis external

events. The “reasonable protection” standard is a means for enabling greater flexibility for

31

addressing the reevaluatedexternal hazards, and in the process, enabling a

beyond-design-basis regulatory framework that establishes an appropriate level of assurance.

The fundamental applicability of the reasonable protection requirement is to equipment that is

relied on for the mitigation strategies for beyond-design-basis events without regard to whether

the equipment is “FLEX equipment” as defined in NEI 12-06 or “plant equipment” as that term is

used in NEI 12-06. Accordingly, the set of requirements that are applicable, and by direct

extension, the resulting level of regulatory assurance required is directly linked to whether the

SSC or equipment is performing a design-basis function or a beyond-design-basis function.

The level of assurance is established by the function performed by the SSC, not by the

equipment or SSC alone.

D. Loss of All Alternating Current Power

The NRC received comments concerning the loss of all ac power requirement in proposed

§ 50.155(b)(1). Several commenters indicated that the assumed damage state for developing

the mitigation strategies and guidelines for beyond-design-basis external events must include a

loss of all power systems including the loss of ac power from batteries through inverters and

direct current (dc) power direct from batteries. The commenters stated that unless this damage

state is assumed, the lessons learned from the Fukushima Dai-ichi event would not be fully

addressed. Another set of commenters stated that the MBDBE proposed rule’s requirements

for a loss of all ac power must be revised to align with the definition of an extended loss of ac

power (ELAP) in the industry guidance document developed for the Mitigation Strategies Order.

In that ELAP definition, power directly or indirectly from batteries is assumed available. These

commenters also suggested that the word “all” should be removed from the MBDBE rule

requirements for “loss of all ac power” to align the requirement with the definition of ELAP.

32

Based on this feedback, the NRC concluded that the MBDBE proposed rule language and

supporting statement of considerations lack clarity and therefore revised the final rule as

discussed in the next paragraph.

The final rule language and sectionSection V.C, “Final Rule Regulatory Bases,” of this

noticedocument are clarified to better convey that the loss of all ac power condition must be

addressed. The first clarification is the deletion of the word “extended” from § 50.155(b)(1)

because the NRC concludes that itthe use of the word “extended” contributed to the confusion

regarding the requirement. Paragraph 50.155(b)(1) requires licensees to assume a loss of all

ac power in developing strategies and guidelines capable of maintaining or restoring the key

safety functions, indefinitely or until the mitigation strategies are no longer needed, including the

acquisition of offsite resources to sustain those functions. As such, the regulation clearly

requires a capability to address an “extended” loss of ac power, and the word “extended” is not

necessary in § 50.155(b)(1). The deletion of the word “extended” is intended to avoid confusion

between the requirement for licensees to address a loss of all ac power and the condition of an

ELAP as defined in the industry guidance. The regulatory guidance for the MBDBE rule,

RG 1.226, addresses the loss of all ac power, including ac power from inverters fed by batteries

or dc power directly from batteries as follows:

1. An ELAP and loss of normal access to the ultimate heat sink (LUHS) (or loss of

access to the normal heat sink for passive power reactor designs)), hereafter referred to

as LUHS, is assumed for the purposes of developing the supporting analysis,

determining the resultant conditions, and establishing times for key actions that support

the development and implementation of mitigation strategies providing additional

capability for beyond-design-basis external events. As discussed above, an ELAP is

33

defined in the industryregulatory guidance as a loss of ac power sources, but assumes

the availability of power directly or indirectly from batteries.

2. To address conditions more severe than the assumed conditions discussed

above (i.e., potentially including loss of power from batteries) and thereby provide a set

of regulatory guidance that implements the loss of all ac power requirement of the

MBDBE rule, the mitigation strategies contain contingencies. These contingencies

involve sending personnel to locally and manually operate non-ac driven core cooling

pumps (e.g., a turbine-driven auxiliary feedwater (TDAFW) or reactor core isolation

cooling pump) to maintain or restore core cooling. These contingencies include the

capability to obtain instrument readings using portable multimeters at locations that do

not rely on the functioning of intervening installed electrical equipment.1

E. Multiple Source Term Dose Assessment

As a result of the NRC’s consideration of NTTF recommendations 9.1 and 9.3, the

proposed MBDBE rule included a requirement for licensees to determine the magnitude of, and

continually assess the impact of, the release of radioactive materials, including from all reactor

core and SFP sources. This proposed requirement is referred to as “multiple source term dose

assessment,” as each source (e.g., core or SFP) has a specific “source term” of radionuclides

that could be released in an accident.

1 There are limitations to what instruments can be repowered by a portable multimeter. While it is possible to

repower, and obtain readings from, a resistance temperature detector or a thermocouple, there are many types of sensors that would need a more specialized type of equipment to accomplish the repowering and measurement. The choice of instrument readings to obtain through these contingencies should allow a licensee to diagnose the symptoms and verify system response to confirm the success of actions taken or to select actions that should be taken in response to the symptoms. Engineering evaluations and/or calculational aids needed to facilitate the interpretation of readings from such instrumentation when taken under the beyond-design-basis external event conditions expected should be performed as part of the planning process for the mitigating strategies, and should identify constraints and limitations of such capabilities, including uncertainties in the results.

34

The NRC received a public comment concerning its § 50.109 backfitting justification for

the proposed multiple source term dose assessment requirements. The comment indicated that

while the NRC had correctly identified these requirements as backfits, it had failed to justify their

proposed imposition as satisfying the criterion under § 50.109(a)(4)(ii) that these proposed

requirements are necessary for adequate protection of public health and safety. The

commenter stated that the NRC’s analysis failed to overcome the presumption that current

regulations and orders ensure adequate protection, and, quoting from noted that the statement

of considerations supporting issuance of the backfit rule in 1988, states that “that presumption

can be overcome only by significant new information or some showing that the regulations do

not address some significant safety issue.” The commenter also noted that beyond the

extensive, required actions that licensees are already taking, the industry is voluntarily

implementing multiple source term dose assessment capabilities to assist in the mitigation of

remote, yet potentially serious beyond-design-basis external events. The commenter stated

that the NRC needs to provide a systematic and documented analysis that imposition of the new

requirements would result in a cost-justified substantial increase in public health and safety.

The NRC agrees that the backfit justification supporting the proposed multiple source

term dose assessment requirements was insufficient. Based on the current emergency

preparedness regulations in 10 CFR part 50, appendix E, “Emergency Planning and

Preparedness for Production and Utilization Facilities,” and the Mitigation Strategies Order

requirements, which were implemented broadly to provide an enhanced onsite emergency

response capability, in combination with the fact that nuclear power reactor licensees have

voluntarily implemented a multiple source term dose assessment capability, the NRC concludes

that there is no evidence of a safety issue that rises to the level of undue risk that would warrant

35

imposition of multiple source term dose assessment requirements as necessary for adequate

protection of public health and safety.

The NRC additionally concludes that imposition of the multiple source term dose

assessment requirement would not provide a substantial increase in the protection of public

health and safety under § 50.109(a)(3).), taking into account the factors in § 50.109(c). This

conclusion is based on the following:

1. For the multiple source term dose assessment requirements to have the potential for

a substantial benefit to the public health and safety, there must first be a substantial

level of risk associated with events that lead to conditions where the contemplated

new requirements to monitor and assess more than a single source term (e.g.,

events that challenge and significantly degrade more than just one reactor core, to

include multiple reactors and/or SFPs) would be used, and therefore shown to

substantially benefit public health and safety.

2.1. The events that would challenge multiple source terms are rare events, and the risk

associated with such events is a very small portion of the total plant risk.

Furthermore, licensees’ implementation of the requirements of the Mitigation

Strategies Order provides a substantially enhanced mitigation capability for these

events and lowers the probability that such rare events would challenge multiple

source terms. These requirements constitute a significant portion of the MBDBE

rule.

3.2. The NRC concludes that the risk of offsite consequences from the beyond-design-

basis events addressed by the rule is very small based upon a review of the recent

work to understand plant risk. This conclusion is based on both the state-of-the-art

reactor consequence analyses (see NUREG-1935, “State-of-the-Art Reactor

36

Consequence Analyses (SOARCA) Report,” November 2012), and the work

performed for the containment protection and release reduction regulatory effort (see

SECY-15-0085, “Evaluation of the Containment Protection & Release Reduction for

Mark I and Mark II Boiling Water Reactors Rulemaking Activities (10 CFR Part 50)

(RIN-3150-AJ26),” dated June 18, 2015, specifically the enclosure entitled,

“Containment Protection and Release Reduction (CPRR) Rulemaking: Draft

Regulatory Basis”). The staff’s evaluation considerstook into account the safety

enhancements related to prevention of radioactive releases that were achieved

through implementation of the Mitigation Strategies Order and implementation of the

requirements of Order EA-13-109, “Order Modifying Licenses with Regard to

Reliable Hardened Containment Vents Capable of Operation under Severe

Conditions,” dated June 6, 2013., in reaching this conclusion.

4.3. Further, the NRC concludes that the portion of overall plant risk associated with the

rare events that might challenge multiple source terms is very small. As a result, the

potential safety enhancement associated with the multiple source term dose

assessment requirements cannot be considered to be substantial.

Accordingly, the NRC concludes that because there iswould not sufficient risk

associated with events that challenge multiple source terms to find thatbe a substantial

additionalincrease in the overall protection toof public health and safety could be achieved

through the imposition of and because the subject requirements. Accordingly, the risk to public

health and safety is very small that backfitting provisions of § 50.109(a)(3)a requirement for

multiple source term dose assessment cannot be satisfiedjustified as a matter of adequate

protection or as a cost-justified substantial safety improvement.

37

Finally, operating plants have installed this multiple source term dose assessment

capability and have committed to maintain the capability. The NRC anticipates that licensees

will maintain this multiple source term assessment capability, even without an explicit

requirement. This installed capability for multiple source term dose assessment is a computer

capability installed in the existing emergency preparedness infrastructure and serves to meet

the existing requirements in appendix E to 10 CFR part 50 to monitor and assess the reactor

source term. The NRC concludes that the optimal regulatory approach for operating licensees

is to continue to maintain the multiple source term dose assessment as a voluntary initiative

following the endorsed guidance that supports this rule.

The final rule was revised to remove the multiple source term dose assessment

requirements.

F. Relocation and Revision toRemoval of the Proposed Staffing and Communications

Requirements

The NRC received public comment that the proposed wording for staffing and

communications requirements to be located in a new section VII of 10 CFR part 50, appendix E

could be interpreted by future readers to mean that those proposed requirements must be

described in the licensee’s emergency plan, notwithstanding the NRC language to the contrary.

A commenter noted that the clarity of these proposed provisions could be improved if they were

moved into § 50.155. The commenter proposed that these requirements could be incorporated

into § 50.155 as a separate sub-paragraph.

The NRC agrees that relocatinglocating the staffing and communications requirements to

§ 50.155 improvesin a new section VII of 10 CFR part 50, appendix E would detract from clarity.

Additionally, the NRC concludesrecognizes that the requirements can be improved by directly

38

linking them to the integrated response capability, which acknowledges the importance of

staffing and communications to effective requirements in the proposed MBDBE rule were not

requirements in the Mitigation Strategies Order. Instead, the issue of staffing was addressed in

the implementation of the Order through the inclusion of regulatory guidance on the subject in

section 11.7 of each version of the industry document NEI 12-06 as endorsed by the respective

versions of JLD-ISG-2012-01 and taken into consideration by licensees in developing and

implementing their strategies and guidelines for . The issue of internal communications was

addressed in section 3.2.2.8 of NEI 12-06 and taken into consideration by licensees in

developing and implementing their strategies and guidelines. The issue of communications

between the site and offsite response organizations was a subject covered in the March 12,

2012 request for information issued under § 50.54(f), which resulted in licensees making

commitments to upgrade their communications capabilities. These upgraded communications

capabilities became part of the licensees’ final integrated plans for the strategies and guidelines

under the Mitigation Strategies Order.

The NRC concludes that the requirements imposed by the Mitigation Strategies Order

were sufficient to provide reasonable assurance of adequate protection and no new information

was developed with regard to staffing and communications that would modify this conclusion.

The NRC concludes that the imposition of requirements for staffing and communications would

not result in a substantial increase in the overall protection of public health and safety or the

common defense and security. This follows the Commission’s direction in SRM-SECY-11-0124

that “[i]n order to be effective, approaches should be flexible and able to accommodate a

diverse range of circumstances and conditions. In consideration of events beyond- the design-

basis external events, and also results in improved alignment with implementation guidance.

The revised and relocated communications and staffing requirements of the final rule more

39

directly align with implementation of the Mitigation Strategies Order. Specifically, successful

implementation of the Mitigation Strategies Order requires sufficient staff and sufficient

communications capability to successfully mitigate a beyond-design-basis external event that

can impact an entire site and adversely impact surrounding telecommunications infrastructure.

The staffing requirement was already in § 50.155(b), so the only change needed was to relocate

the communications requirements to § 50.155(c)(4) and link them to the implementation of the

mitigation strategies and guidelines required by § 50.155(b)(1) and (b)(2). , a regulatory

approach founded on performance-based requirements will foster development of the most

effective and efficient, site-specific mitigation strategies, similar to how the agency approached

the approval of licensee response strategies for the ‘loss of large area’ event under its B.5.b

program.” As a result, the imposition of requirements for staffing and communications would not

meet the provisions of the Backfit Rule.

Staffing for the EDMGs of § 50.155(b)(3) in the final rule had been included in the on-

shift staffing analysis requirements of the “Enhancements to Emergency Preparedness

Regulations” final rule (76 FR 72559; November 23, 2011) when the requirements of

§ 50.155(b)(3) were still in § 50.54(hh)(2). The proposed MBDBE requirements for applicants

and/or licensees to perform staffing analyses and to make and describe communication

systems capabilities, are not included as requirements in the final MBDBE rule, but are

addressed instead in the supporting guidance. The staffing analyses and communication

capability assessments are effective means for initially establishing the staff and

communications capabilities for the MBDBE rule. However, for the MBDBE rule, performance-

based requirements that directly link staffing and communications to successful implementation

of the mitigation strategies are a better means for making these requirements generically

applicable and provide greater assurance that these capabilities are maintained. While future

40

applicants may find it beneficial to use such staffing analyses and communication capability

assessments to initially establish these capabilities, some advanced designs may rely less on

staff and communications capabilities; therefore, keeping these analyses in guidance rather

than creating a requirement removes the potential need for an exemption for a future design

with such attributes.

The NRC concludes that relocating the staffing and communications requirements to

§ 50.155 improves the clarity of the MBDBE rule by removing the confusion created by their

proposed location in appendix E to 10 CFR part 50. Further, linking these requirements directly

to the mitigation strategies facilitates the maintenance of these capabilities as changes are

made to the implementation of the MBDBE requirements. Recognizing that the staffing and

communications requirements in the MBDBE rule were not explicit requirements in the

Mitigation Strategies Order, even though both were considered and addressed as part of

implementation of the Order, the NRC addressed these requirements in the supporting

backfitting and issue finality assessment.

Flexible Scheduling Provisions and The final rule was revised to remove the staffing and

communications requirements.

G. Cumulative Effects of Regulation Feedback, Removal of Requirements for Drills or

Exercises, and Withdrawal of Orders

The NRC was aware that the nuclear industry would be challenged by the proposed

2-year compliance date for the MBDBE rule, and requested feedback focused on whether this

provided sufficient time to address the reevaluated hazard information. Additionally, the

41

proposed rule contained the standard CER questions that also sought feedback on whether the

implementation of the MBDBE requirements might involve CER.

The NRC received feedback that the NRC received indicatesindicated that the degree to

which the proposed reevaluated seismic or flooding hazards maycould impact the

implementation of mitigation strategies varies widely across the operating reactor fleet, and the

various evaluations necessary to prepare for any necessary modifications are in different stages

of completion. For example:

• The NRC is continuingconsidered using a flexible scheduling provision in the final

rule to evaluate the flooding hazard reevaluationsaddress this concern but concluded

that have been submitted. In some cases, extended schedules were this would not

be necessary to develop these evaluations, in part because of detailed modeling that

was conducted by in light of the U.S. Army Corpsremoval of Engineers. An initial

NRC evaluation of these reevaluations is necessary before licensees move forward

with their use in assessing mitigation strategies.

• While some sites have simple evaluations whererequirements to address the

reevaluated hazards are bounded byfrom the design basis of the facility, such that

the mitigation strategies would already comply with the reevaluated hazards portion

of the MBDBE rule in advance of the effective date of thefinal rule, others must

complete additional evaluations. For such sites where the reevaluated hazards

exceed the design basis of the facility, licensees must perform detailed assessments

to evaluate the effect of the external hazard on their mitigation strategies.

• For some sites, there is still a need to develop the methodology needed to perform

the assessments of their mitigation strategies. This situation applies to assessments

of seismic reevaluated hazards that use the risk-informed “path 5” approach in

42

RG 1.226, where there may be a need to base such an approach on a seismic

probabilistic risk assessment, which is currently in progress. The 2-year

implementation timeline would clearly not provide adequate time for review of the

seismic probabilistic risk assessment results by the NRC staff prior to completion of

the licensee’s modifications under the final rule.

The NRC also received feedback that completion of the engineering, design, planning

and installation of any identified modifications or other plant changes is a complex process.

Sufficient time should be provided to complete the work efficiently, for example:

• Licensees will not start the modification process until their mitigation strategies

assessments have been approved by the NRC.

• If greater than minor modifications are indicated, a 2-year implementation window

would tend to require that the modifications be performed at risk or fast-tracked,

where engineering and design would be performed in parallel with installation of the

change. This is inefficient and unnecessarily increases the risk for errors and

rework.

In light of these concerns associated with addressing the reevaluated hazards

information, feedback was provided to the NRC that recommended the MBDBE rule allow each

licensee to develop and submit to the NRC a unit-specific implementation schedule to account

for site-specific variations. It was suggested that within 90 days of the effective date of the rule,

each holder of an operating license would submit a schedule for achieving full compliance with

the requirements of § 50.155.

. From a more general perspective, CER feedback indicated that circumstances of each

plant’s implementation of the final rule requirements would be unique and there may be

43

instances where licensees would need to request additional time for full implementation of the

rule. One commenter stated that there will likely be instances where conflicts will arise in the

implementation of the MBDBE rule requirements, and that the NRC should allow licensees the

latitude to resolve the conflicts in a manner that best meets the objectives of safety and security,

including allowing licensees to prioritize regulatory activities where conflicts in schedule are

identified, or provide alternative means for compliance in instances where conflicts require an

alternative to be established. The commenter also advocated that the NRC support the use of

risk-informed decision making consistent with the Commission direction on SECY-15-0050,

“Cumulative Effects of Regulation Process Enhancements and Risk Prioritization Initiative,”

dated April 1, 2015.

Other CER feedback concerned a potential unintended consequence that may occur if

implementation of the MBDBE rule conflicts with the existing order requirements. The

commenter said that the NRC should set forth a transparent transition from the Mitigation

Strategies and SFPI Orders to § 50.155. SomeAll operating power reactor licensees have

already achieved compliance with the orders using approved guidance (JLD-ISG-2012-01,

“Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for

Mitigation Strategies for Beyond-Design-Basis External Events,” and JLD-ISG-2012-03,

“Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation”). The MBDBE

rule and the supporting RGs could be perceived to specify actions that are in addition to, or

different from, the actions taken by licensees following the approved guidance to achieve

compliance with the NRC orders, including actions that could be less restrictive than the

corresponding actions needed for compliance with the orders. Further, the NRC received a

comment that there is a lack of clarity regarding the difference between compliance with the

orders and issuance of § 50.155 and the associated RGs. To avoid unintended consequences

44

associated with two similar—but potentially not identical—sets of requirements, it was

commented that the NRC should rescindwithdraw the Mitigation Strategies and SFPI Orders

once § 50.155 becomes effective.

Additionally, stakeholders provided CER feedback concerning a potential schedule

conflict for new plants regarding the need to perform analyses that were proposed as section VII

to 10 CFR part 50, appendix E and the completion of the inspections, tests, and analyses under

the 10 CFR part 52 framework.

Finally, the NRC held a public meeting to discuss CER. During this meeting, a

representative of the Boiling-Water Reactor Owners Group pointed out that those licensees that

received Order EA-13-109, which was issued more than a year after the Mitigation Strategies

and SFPI Orders, would have less time after attaining full compliance with Order EA-13-109

than other licensees to complete training and verify that they have completed all preparations to

comply with the MBDBE rule.

The NRC agrees that the current state of licensee implementation of regulatory actions

taken following the March 2011 Fukushima Dai-ichi event varies widely across the industry. For

many licensees, addressing the reevaluated hazard information is the primary driver of the

implementation schedule. The proposal to allow each licensee to submit an implementation

schedule to the NRC is an approach that has been used for past regulations, and the NRC

agrees that it enables sufficient flexibility to address potential CER issues and removes the

need for unnecessary resource expenditure on regulatory approval of schedule exemptions.

The final rule is revised to provide a flexible schedule option in § 50.155(h)(2).

Recognizing that the schedule flexibility may still not address all situations that arise, the

provisions of § 50.12, “Specific exemptions,” can address such circumstances. In this regard,

the NRC reiterates its support for risk-informed approaches for such submittals.

45

The NRC furtherThe NRC agrees that the group of licensees that received Order EA-13-

109 would achieve full compliance with each of the orders issued in response to the Fukushima

Dai-ichi event approximately one year after the remaining licensees. In order to alleviate CER

for this group of licensees, the final rule is revised to provide an additional year for

implementation, giving this group of licensees the same amount of time after full compliance

with the orders to attain compliance with the rule.

The NRC also agrees that redundancy would exist between requirements in the

Mitigation Strategies and SFPI Orders and those in the MBDBE rule. The final rule contains

language that is intended to ensure a smooth transition between the order requirements and the

MBDBE rule, including rescindingwithdrawing the orders, to alleviate this issue.

Finally, the schedule issue associated with new reactors was resolved as a result of the

relocation of and revision toremoval of the staffing and communication requirements in favor of

their treatment in the regulatory guidance for the rule. As a result of the revision made to the

MBDBE rule, the scheduling requirements that were of concern, are removedno longer

operative.

Additionally, the NRC received feedback suggesting that licensees that received Order

EA-13-109 be allowed an additional year for conducting thean initial drill or exercise under

§ 50.155(e)(4).the proposed rule. Holders of operating licenses for power reactors (including

those that received Order EA-13-109) arewould have been required to conduct thean initial drill

or exercise within 4 years of the effective date of the final MBDBE rule under this paragraph.

During this implementation period, holders of operating licenses for power reactors will have

conducted two biennial emergency preparedness exercises under 10 CFR part 50, appendix E,

section F.2.b. This requirement for biennial exercises includes a requirement to The NRC noted

that the conduct additionalof drills between the exercises. These drills must involve a

46

combination of some of the principal functional areas of the licensee’s onsite emergency

response capabilities, which include management and coordination of emergency response,

accident assessment, event classification, notification of offsite authorities, assessment of the

onsite and offsite impacts of radiological releases, protective action recommendation

development, protective action decision making, plant system repair, and mitigative action

implementation. In light of the existing, continuing requirements for emergency preparedness

drills and exercises or exercises was not included as a requirement in the 4-year period

following the effective date of the final MBDBE rule and the available synergies between the

elements of that program and the elements that must be Mitigation Strategies Order, instead

being an element of an acceptable approach to meeting the order’s requirement for training.

Drills are addressed in the initial drill under § 50.155(e)(4), the NRC concludes that there would

be minimal CER impactregulatory guidance for the Mitigation Strategies order contained in

retaining the requirement for performance within the 4 years following the effective date of the

rule. No changes were madesection 11.6.5 of NEI 12-06, as endorsed by JLD-ISG-2012-01

and carried forward to the regulatory guidance for the final rule. NEI 12-06, Revisions 0 and 2

contained guidance on the content and periodicity of these drills, specifying the same 8-year

period as was proposed for this rule. NEI 12-06, Revision 4, which is endorsed by the final

MBDBE rule as a result ofversion of Regulatory Guide 1.226, incorporates by reference further

guidance on the performance of drills contained in the industry document NEI 13-06, Revision 1,

“Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and

Events,” which also specifies the 8-year period that was proposed for drill performance for this

feedbackrule. In addition, NEI 12-06, Revisions 2 and 4 include guidance on the validation of

time sensitive actions in appendix E. Validation of the time sensitive actions has been

performed by all operating power reactor licensees in order to ascertain that they are capable of

47

executing the time sensitive actions necessary to perform the strategies and guidelines required

under the Mitigation Strategies Order and under the final rule in sufficient time to meet the time

constraints determined by a plant-specific thermal-hydraulic analysis. These validations

included, for example, the use of timed drills in simulators for control room actions or physical

walkthroughs for actions in the field to demonstrate that the operating staff could perform the

time sensitive actions within the identified time constraints.

The NRC concludes that the requirements imposed by the Mitigation Strategies Order

were sufficient to provide reasonable assurance of adequate protection and no new information

was developed with regard to drills or exercises that would modify this conclusion. The NRC

similarly concludes that imposing a requirement for drills and exercises would not provide a

substantial increase in the overall protection of public health and safety. Therefore, the

imposition of a requirement for drills or exercises would not meet the provisions of the Backfit

Rule. The requirement for drills and exercises has been removed from the final rule. The

removal of the requirement for an initial drill or exercise from the final rule addresses the

commenter’s concerns with scheduling of drills for licensees that received Order EA-13-109.

The NRC also received feedback on CER suggesting that the flexible scheduling

provisions of § 50.155(h)(2) be extended to licensees that received Order EA-13-109 for

reasons other than addressing reevaluated hazards. As discussed above, the NRC modified

the implementation time under § 50.155(h)(1) for licensees that received Order EA-13-109 to

allow an additional year for this group of licensees.No changes were made to the final MBDBE

rule as a result of this feedback. The NRC concludes that any need for further schedule

flexibility can be addressed under § 50.12 on an individual basis if it becomes necessary.

The final rule has been modified to allow one additional year for implementation for

operating power reactor licensees that received NRC Order EA-13-109, to remove the proposed

48

requirement for drills or exercises, and to provide for the withdrawal of the Mitigation Strategies

and SFPI Orders and associated license conditions.

H. Change Control Enhancements

The NRC requested and received comments on the proposed MBDBE change control

provisions. Commenters suggested that the NRC should consider a “prior review and approval”

type of regulatory approach, and cited as an example the “reduction in effectiveness” criterion

that is used in several existing change control requirements. The concern expressed by

commenters is associated with the potential for licensees to make changes to the

implementation of the MBDBE rule requirements that are outside endorsed guidance. Another

commenter echoed this concern, citing examples of licensees not properly implementing the

mitigation strategies and citing violations associated with the implementation of the

requirements of § 50.59, “Changes, tests, and experiments.” The NRC also received a

comment recommending a reporting requirement be part of the change control provisions. The

NRC received comments concerning the statement of considerations, which confused

stakeholders and suggested that prior review and approval may still be required. Finally, the

NRC received comments suggesting revisions to the change control requirements that were

intended to clarify the requirements.

The NRC finds that its basic approach to change control does not need revision.

Specifically, the NRC continues to conclude that it does not need to include reporting

requirements or criteria for prior NRC review and approval of changes. The suggestion for use

of a “reduction in effectiveness” criterion was understood to be an example of a “prior review

and approval” type criterion, and the NRC considered both of those specific examples and any

others that it could identify. First, the NRC concluded that use of a “reduction in effectiveness”

49

or equivalent type of change control criterion would not clearly differentiate significant changes

(that would warrant NRC prior review) from changes not warranting prior review.

Second, given the deterministic regulatory approach followed for development and

implementation of the strategies under the Mitigation Strategies Order, many potential changes

could have aspects that tend to reduce the effectiveness while also having aspects that tend to

improve the effectiveness of the mitigation strategies. For example, replacing a portable

diesel-driven pump with a similar one of a larger size could improve the effectiveness of a

mitigation strategy by allowing for greater flow rates of makeup water, but reduce its

effectiveness because of a higher fuel usage rate and an associated shorter run time without

refueling. Judging such changes using a prior review and approval type of approach is

challenging at best and would very likely result in an unwarranted diversion of licensee and

NRC resources to review and approve changes.

Other beyond-design-basis provisions currently applicable to operating reactors in

§ 50.62, “Requirements for reduction of risk from anticipated transients without scram (ATWS)

events for light-water-cooled nuclear power plants,” § 50.63, and § 50.54(hh) do not contain

change control requirements. The only comparable set of requirements addressing beyond-

design-basis events containing provisions that address the control of changes is § 50.150,

“Aircraft impact assessment,” which is applicable to new reactors. Reviewing that requirement,

and noting that § 50.150the Aircraft Impact Assessment Rule requires that changes meet

thecertain assessment requirements contained within § 50.150, the NRC concluded that the

provisions in § 50.155(gf) for documentation of changes are well aligned with the

§ 50.150Aircraft Impact Assessment Rule’s control of changes provisions because the NRC is

requiring that changes be demonstrated to satisfy the requirements of § 50.155.

50

Finally, the NRC concludes that its regulatory approach that relies on inspection and

enforcement will identify any substantial problems with a licensee’s MBDBE change control

process well before such problems present a safety problem. The NRC anticipates that

changes will be infrequent and that those that occur will be consistent with endorsed guidance

or apply approved alternatives. Inspection and enforcement is an effective regulatory approach

for identifying and addressing situations in which licensees fail to meet these expectations.

Based on consideration of the feedback provided, the NRC did not find a suitable criterion (or

criteria) that the NRC judged would result in a substantial improvement over what was proposed

for addressing changes in the proposed rule, and accordingly the final rule continues with the

same approach: licensees must demonstrate that the proposed change will result in continued

compliance with the requirements of § 50.155, licensees must maintain documentation of those

changes, and the NRC will oversee through inspection the changes and take enforcement

action as appropriate.

Notwithstanding this conclusion, the NRC clarified sectionSection VI of this

noticedocument to address changes that apply neither to endorsed guidance nor approved

alternatives. This section now includes examples of cases that the NRC concludes would not

result in demonstrated compliance.

The NRC also concludes that a change control reporting requirement is not necessary in

the MBDBE rule. Licensees will not need to report changes to the mitigation strategies because

of the NRC’s planned oversight of the maintenance of the resulting strategies through inspection

and enforcement under the Reactor Oversight Process. Such a requirement would be an

unnecessary reporting burden, and instead, the MBDBE rule requires licensees to maintain

documentation of such changes, which the NRC can inspect.

51

The NRC agrees that there was confusion created when it described the potential for

licensees that may wish to consult with the NRC concerning changes to the implementation of

the MBDBE rule requirements. This was not intended to suggest that the NRC was requiring a

prior review of changes, and this noticedocument is revised accordingly.

Finally, the NRC agrees with suggested revisions to the change control provisions that

result in clarification of the requirements. The NRC clarified the final requirements to refer to

them as “Documentation of Changes,” simplified the provisions by combining two of the

proposed provisions, clarified the provision that addresses the application of other change

control processes, and removed the word “all” from the rule regarding the need to maintain

documentation of changes. As a result, the NRC concludes it is necessary to provide additional

description in the statement of considerations to clarify what constitutes a “change” with regard

to the documentation that the NRC requires licensees to maintain. Changes to the

implementation of the MBDBE requirements that do not result in a significant change to the

functional performance of the equipment and also do not significantly impact the strategies and

guidelines would not constitute a “change” for this purpose. The NRC recognizes that licensees

would maintain all of this documentation as part of their normal procurement and configuration

control processes, but for the regulatory purposes of § 50.155(gf), these types of changes would

not be significant in terms of implementation of the MBDBE requirements. For example, a

replacement of a FLEX pump with a pump having the equivalent functional performance (i.e., no

significant impact to functional performance), equivalent weight, size, and mobility (i.e., no

significant impact to staging and deploying the pump), and equivalent connections would not

constitute a “change” for the purposes of § 50.155(gf).

I. Spent Fuel Pool Instrumentation Requirements

52

The NRC received several comments that the MBDBE rule must keep the requirements

for SFPI separate and distinct from the requirements for mitigation strategies. The commenters

noted that the requirement for SFPI was promulgated by the SFPI Order, while the requirement

for mitigation strategies was promulgated by the Mitigation Strategies Order. The commenters

further noted that while the two orders were in response to lessons learned from the Fukushima

Dai-ichi event, they are distinctly different in underlying purpose and character.

The NRC agrees with these comments and revised the final rule to keep SFPI and

mitigation strategies requirements separate. The MBDBE rule provisions in § 50.155(b)(1),

which were initially imposed through the Mitigation Strategies Order, require strategies and

guidelines to maintain or restore core cooling, containment, and SFP cooling capabilities for

beyond-design-basis external events, and these requirements are independent of those initially

imposed in the SFPI Order and now located in § 50.155(fe). The SFPI requirements ensure

that information regarding the SFP is provided to decision makers to enable the prioritization of

resources. The SFPI requirements were not intended to support mitigation action, but to simply

provide information. Accordingly, the NRC moved the SFPI requirement to § 50.155(fe) and

decoupled the requirement from § 50.155(b)(1) to ensure it remains independent of mitigation

strategies requirements.

As part of the industry response to the Mitigation Strategies Order, licensees used the

SFPI to support mitigation strategies to maintain or restore SFP cooling. If licensees use the

SFPI to comply with § 50.155(b)(1), then the SFPI would be subject to the requirements of

§ 50.155(b)(1) and, if applicable, § 50.155(b)(2). This application of § 50.155(b)(2) to SFPI is

limited to these circumstances (i.e., voluntary use of SFPI to comply with § 50.155(b)(1))

because the Commission affirmed that the reevaluated hazard information be considered within

only the mitigation strategies in the SRM dated March 30, 2015, associated with

53

COMSECY-14-0037, “Integration of Mitigating Strategies for Beyond-Design-Basis External

Events and The Reevaluation of Flooding Hazards,” dated November 21, 2014.).

J. Drill Frequency

The NRC received comments regarding the proposed 8-year frequency for performance

of drills under § 50.155(e).the proposed rule. One commenter expressed the view that there is

a relatively high frequency of extreme events, and given the potentially high consequences

associated with such events, the final rule must require an exercise interval no longer than once

every 3 years. The commenter noted that an 8-year frequency was too infrequent, resulting in a

steady decline in capabilities between tests. Finally, the commenter expressed the view that

these drills need to be comprehensive and as realistic as possible.

Another commenter suggested drills be conducted annually or every 2 years. The

remaining commenters supported the proposed 8-year frequency.

TheAs discussed in Section IV.G, “Cumulative Effects of Regulation Feedback, Removal

of Requirements for Drills or Exercises, and Withdrawal of Orders,” of this document, the NRC

concludes that the requirements imposed by the Mitigation Strategies Order were sufficient to

provide reasonable assurance of adequate protection of public health and safety and no new

information was developed with regard to drills or exercises that would modify this conclusion.

The NRC then considered whether there would be a substantial increase in the overall

protection of the public health and safety or the common defense and security that would result

from including requirements in the final rule for drills or exercises rather than continuing the

practice of addressing them in the regulatory guidance as had been done for the Mitigation

Strategies Order. The NRC concluded that, while there would be some benefit in the form of

clarity as to what had been found acceptable for compliance with the orders being made

54

generically applicable in this rulemaking, the recharacterization of drills or exercises from

regulatory guidance to requirements would not constitute a substantial increase in the overall

protection of the public health and safety or the common defense and security.

Because of this, the NRC concludes that a separate requirement for drills or exercises

would not be needed, but could constrain an existing licensee or an applicant for a new licensee

from developing innovative mitigation strategies that do not rely on staffing or communications.

This follows the Commission’s direction in SRM-SECY-11-0124 that “[i]n order to be effective,

approaches should be flexible and able to accommodate a diverse range of circumstances and

conditions. In consideration of events beyond the design basis, a regulatory approach founded

on performance-based requirements will foster development of the most effective and efficient,

site-specific mitigation strategies, similar to how the agency approached the approval of

licensee response strategies for the ‘loss of large area’ event under its B.5.b program.”

In addition, the NRC did not revise the MBDBE drill frequency because it is specified in

the regulatory guidance for the final rule in response to these comments. The NRC

judgedconcluded that the 8-year frequency, and use of a drill rather than an exercise

requirement as the minimum requirement, provides for the appropriate level of regulatory

assurance for the MBDBE rule and is aligned with the frequency of similar current emergency

preparedness exercise requirements. While the NRC recognizes that a requirement for more

frequent, comprehensive, and realistic drills or exercises would provide a higher level of

assurance that licensees are maintaining the MBDBE requirements, the NRC is also sensitive to

diverting limited licensee resources from activities that have greater importance to public health

and safety. The NRC concluded that the MBDBE drill requirementperiodicity strikes the correct

balance in terms of providing an appropriate level of regulatory assurance, and, by aligning with

the current emergency preparedness exercise requirements, it provides licensees with flexibility

55

should they choose to implement the drill requirementsdrills in conjunction with emergency

preparedness drills or exercises.

Additionally, the NRC concludes that the MBDBE drill requirements should be viewed in

the larger context of the training requirements in the MBDBE rule that include the use of the

systems approach to training (SAT) as defined in § 55.4, “Definitions,” which provides a

feedback mechanism to increase the frequency of training and other performance-enhancing

experiences such as drills or exercises, if necessary.

K. Consideration of Explicit Requirements for a Three-Phase Response

The NRC received a comment that the MBDBE rule should maintain the three-phase

response structure for mitigation that was described in the Mitigation Strategies Order rather

than use the proposed rule’s performance-based requirements. The commenter stated that the

substitution of “higher level, performance-based requirements” reduces confidence that the

MBDBE measures will be successful if needed. It is the commenter‘s view that the nuclear

industry and the NRC have consistently disagreed on what constitutes appropriate

compensatory measures and associated administrative controls and provided an example to

support the comment. The commenter expressed the view that the three-phase structure

provides clearer definition of what is expected, better enabling licensees to meet those

expectations and NRC inspectors to independently verify that this desired outcome has been

achieved.

The NRC did not revise the MBDBE rule as a result of this comment. The issuance of the

Mitigation Strategies Order included a separate attachment 3 for the imposition of requirements

on Vogtle Electric Generating Plant, Units 3 and 4 to reflect their use of the AP1000 design. In

the Mitigation Strategies Order, attachment 3, the NRC documented that the inherent features

56

of the AP1000 design obviate the need for phase two of the three-phase response required of

currently operating power reactors that is addressed in attachment 2 of the Mitigation Strategies

Order. The RG 1.226 provides implementation guidance for the three-phase approach as one

acceptable method of complying with the MBDBE rule. Future designers may be able to

develop and implement strategies and guidelines that do not rely on a three-phase approach,

and may propose alternative approaches as updates to the existing guidance or in their

applications.

This framework is consistent with the Commission’s direction in SRM-SECY-11-0124 to

follow performance-based approaches for beyond-design-basis events, while harmonizing the

treatment of currently operating and new power reactors. Such approaches allow greater

flexibility and enable more effective and efficient implementation of the requirements. The NRC,

through its current review, audit, and inspection activities supporting implementation of the

Mitigation Strategies Order, is identifying differences of interpretation such as those noted by

the commenter and ensuring that they are resolved.

L. Clarifications to Decommissioning Provisions

The NRC received comments concerning the proposed MBDBE provisions in

§ 50.155(a)(3) regarding the applicability of the MBDBE rule to licensees with reactors in a

decommissioning phase. The commenters agreed with the underlying approach to the MBDBE

decommissioning provision and suggested revisions to clarify those provisions and eliminate

unnecessary language.

The NRC agrees with some of the suggestions, and the final rule reflects those changes.

Paragraph 50.155(a)(2) in the final rule explicitly identifies which portions of the MBDBE rule

apply to a licensee as it proceeds through the decommissioning process.

57

M. Clarifications to Equipment Requirements and Removal of Proposed Maintenance

Requirement

The NRC requested feedback concerning the proposed maintenance provision in

§ 50.155(c)(3). The Mitigation Strategies Order did not contain a specific maintenance

requirement, but instead contained a performance-based requirement “to develop, implement

and maintain strategies.” This same language was included in proposed § 50.155(b)(1), so that

a failure to perform adequate maintenance would likely lead to a failure to meet this

requirement.

The feedback indicated that commenters did not see a need for a separate maintenance

provision in § 50.155(c)(3) for the § 50.155(b)(1) equipment. Commenters noted that the

proposed maintenance requirement of § 50.155(b), along with the guidance in NEI 12-06, as

endorsed by JLD-ISG-2012-01 for the Mitigation Strategies Order (now endorsed in RG 1.226),

adequately addresses equipment maintenance. The NRC agrees with this feedback. The

intent is to carry forward the maintenance requirements of the Mitigation Strategies Order as it

was included within the order’s requirement for licensees to develop, implement, and

accordinglymaintain the strategies. The corresponding requirement for development,

implementation and maintenance of the strategies is included in § 50.155(b) and the proposed

separate maintenance requirement is removed from the final rule.

Regarding maintenance, the NRC also received feedback suggesting that the MBDBE

rule be revised to state that the Maintenance Rule, § 50.65, “Requirements for monitoring the

effectiveness of maintenance at nuclear power plants,” does not apply to FLEX equipment or

SFPI whose primary design function is to support strategies developed to solely comply with the

MBDBE rule. The NRC agrees that the criteria in § 50.65(b) do not include FLEX equipment in

58

the scope of § 50.65 if the FLEX equipment is used solely for compliance with § 50.155.2

Accordingly, the suggested revision is not necessary. Furthermore, such an addition could

result in complications if a licensee chooses to use FLEX equipment in a future regulatory

application (separate from § 50.155) that would result in the equipment meeting the scoping

criteria in § 50.65.

In response to one comment, the NRC changed § 50.155(c)(1) in the final rule to more

clearly communicate the equipment capacity and capability requirements. One of the changes

extends the capacity and capability requirements to § 50.155(b)(2) because the § 50.155(b)(2)

requirements cannot be satisfied unless the equipment credited in § 50.155(b)(2) has sufficient

capacity and capability. The remaining changes to paragraph (c) in § 50.155 are discussed in

the “Reasonable Protection,” “Spent Fuel Pool Instrumentation,” and “RelocatingRemoval of the

2 In the event that a licensee relies upon the mitigation strategies equipment for other purposes such as mitigation

of a design-basis event, the application of scoping criteria for reliance on the equipment for those purposes would govern. As a result, equipment that has dualmultiple purposes could have design-basis functions that fall within the scope of § 50.65the Maintenance Rule for one purpose, while being out of and a mitigation strategy function that is not covered by the Maintenance Rule, but instead within scope for the purpose of use in the mitigation strategies.maintenance programs established under § 50.155 through the guidance of Regulatory Guide 1.226 and NEI 12-06. For example, a turbine-driven auxiliary feedwater (TDAFW) pump in a pressurized-water reactor would fall within the scope of the monitoring requirements of § 50.65(a) under the criteria of § 50.65(b) for those functions that meet the criteria, but not for the performance of beyond-design basis functions for the strategies and guidelines required by § 50.155. As a result, the monitoring under § 50.65(a) would be with the goal of providing reasonable assurance that the TDAFW pump is capable of fulfilling its intended safety function (i.e., specific function) within the reference bounds of the design bases as defined in § 50.2 for the functions that result in its inclusion in the scope of § 50.65. The capability of the TDAFW pump to remain functional in the context of a loss of all ac power concurrent with an LUHS, which could expose the pump to environmental and operational constraints outside the reference bounds of the design bases for the events resulting in inclusion in the scope of § 50.65(a) due to a longer period with an absence of normally available cooling, would not be addressed by the § 50.65(a) monitoring program, but instead by the maintenance and testing programs established under § 50.155 through the guidance of RG 1.226 and NEI 12-06.

Similarly, some licensees rely on a portable, ac-power independent pump for the strategies and guidelines developed under § 50.155(b)(1), (2), or (3). These strategies and guidelines may be referred to in the licensee’s EOPs, but are not necessary in order to conform to the NRC-approved emergency planning guidelines that form the basis for the EOPs. Therefore, because the portable, ac-power independent pump is not used in the EOPs, it would not be one of the nonsafety-related SSCs included within the scope of § 50.65(a)(1) under § 50.65(b)(2)(i), unless otherwise required by § 50.65(b). Further details on scoping of equipment under the § 50.65 are provided in NUMARC 93-01, “Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants.”

59

Proposed Staffing and Communications Requirements” sections of this portion of the

noticedocument.

N. Removal of Integration Requirements

In the Proposed MBDBE Rule, the NRC had included a potential requirement for an

overarching integrated response capability including the mitigation strategies for beyond-design-

basis external events and the EDMGs and an organizational structure specific to the integrated

response capability. In addition, the Proposed MBDBE Rule included a potential requirement

for integration of the integrated response capability with the existing emergency operating

procedures. In reexamining the requirements of the Proposed MBDBE Rule, the NRC

recognized that the implementation of the strategies and guidelines under Order EA-02-026,

“Interim Safeguards and Security Compensatory Measures,” dated February 25, 2002, which

resulted in the EDMGs included in § 50.155(b)(2), and the implementation of the strategies and

guidelines under the Mitigation Strategies Order that constitute the remainder of the proposed

integrated response capability, had both included a need for integration at the regulatory

guidance level. For example, the regulatory guidance in NEI 12-06 for the Mitigation Strategies

Order covers the interactions between the procedures developed under the order and their

interfaces with various accident mitigation procedures to result in an overall coherent and

comprehensive structure in section 11.4, “Procedure Guidance.” In addition, this regulatory

guidance, which provides one acceptable means of complying with the order, includes a need

for validation of the resulting strategies to show they are feasible; this validation included drills

and walkthroughs of the resulting procedural documentation to show that it can be executed by

the personnel that would need to use the strategies in an actual event. The NRC concludes that

the requirements imposed by the Mitigation Strategies and the Interim Safeguards and Security

60

Compensatory Measures Orders were sufficient to provide reasonable assurance of adequate

protection and no new information was developed with regard to integration that would modify

this conclusion. In addition, the NRC concludes that requirements for integration would not

result in a substantial increase in the overall protection of public health and safety. Therefore,

imposing requirements for an integrated response capability and integration with the existing

emergency operating procedures would not meet the provisions of the Backfit Rule. The final

rule has been revised to remove the proposed requirements for an integrated response

capability and integration with the existing emergency operating procedures.

O. Training

The Proposed MBDBE Rule included potential requirements for training that included

qualification of personnel and the use of the systems approach to training as defined in § 55.4 of

this chapter. The training requirement in the proposed rule carried forward a requirement for

training from the Mitigation Strategies Order. The elements of this requirement for qualification

and the use of the systems approach to training were addressed in the regulatory guidance for

the Mitigation Strategies Order. The NRC concluded that the requirements imposed by the

Orders were sufficient to provide reasonable assurance of adequate protection of public health

and safety and no new information was developed with regard to qualification or the systems

approach to training that would modify this conclusion. The NRC also considered whether there

would be a substantial increase in the overall protection of the public health and safety or the

common defense and security that would result from including requirements in the final rule for

qualification or the systems approach to training rather than continuing the practice of

addressing them in the regulatory guidance as had been done for the orders. The NRC

concluded that, while there would be some benefit in the form of clarity as to what had been

61

found acceptable for compliance with the orders being made generically applicable in this

rulemaking, the recharacterization of those items from regulatory guidance to requirements

would not constitute a substantial increase in the overall protection of the public health and

safety or the common defense and security.

The NRC concludes that a separate requirement for qualification and the systems

approach to training is not needed, but could constrain an existing licensee or an applicant for a

new licensee from developing innovative mitigation strategies that do not rely on them. This

follows the Commission’s direction in SRM-SECY-11-0124 that “[i]n order to be effective,

approaches should be flexible and able to accommodate a diverse range of circumstances and

conditions. In consideration of events beyond the design basis, a regulatory approach founded

on performance-based requirements will foster development of the most effective and efficient,

site-specific mitigation strategies, similar to how the agency approached the approval of

licensee response strategies for the ‘loss of large area’ event under its B.5.b program.” The

final rule has been revised to remove requirements for qualification and the use of the systems

approach to training.

N.P. Discussion of Four Topics that Were Addressed Generically Dispositioned

The NRC received a number of comments that fell into four topical areas. The comments

were considered and addressed generically dispositioned. These comments did not result in

changes to the MBDBE rule. A discussion of these topics is provided below.

1. Comments that Suggest a Completely Different Approach to Mitigation of

Beyond-Design-Basis Events

Several commenters provided feedback that the MBDBE rule should contain

requirements that address various specific external events. The suggestions included

62

geomagnetic disturbances (which are addressed separately in section III, “Petitions for

Rulemaking,” of this noticedocument because they are the subject of a petition for rulemaking

currently under consideration by the NRC), cyber events that might disable the electric grid,

attacks involving devices that may disable the electric grid, malicious attacks on a nuclear

facility, and explosions from gas lines running in the vicinity of a nuclear facility. In all cases, the

NRC response to this feedback is the same. These comments fundamentally suggest that the

NRC take a different regulatory approach in the MBDBE rule than the NRC took under the

Mitigation Strategies Order following the Fukushima Dai-ichi event. While theThe comments

tend to explicitly identify external events or conditions that commenters believe should be

addressed by the MBDBE rule, the practical effect of fully addressing these comments would be

for the NRC to revisit the possible set of external events that might occur, identify which of these

events from the entire set should be in scope of the MBDBE rule, establish mitigation strategies

requirements that include the proposed additional events, and then specifically establish

requirements for the damage states and conditions that are postulated to stem from the

proposed additional set of events..

Rather than following the approach suggested by these commenters, the NRC is

continuing with the regulatory approach taken with the issuance of the Mitigation Strategies

Order. The order requires licensees to postulate a challenging damage state that exceeds the

design basis, and to develop and implement the mitigation strategies to address that damage

state. These strategies give licensees a capability for the mitigation of beyond-design-basis

external events. This regulatory approach provides additional mitigation capability as well.

Given the fundamentally unbounded nature of the beyond-design-basis external events to which

these requirements are directed, the NRC determined that licensees need to address

uncertainty by assuming a challenging damage state that such events might create, and then

63

adding to that damage state the consideration of the effects the initiating event may have on the

physical protection of equipment and strategies. For a more detailed explanation of this

response, refer to the NRC response to General Comment 9 in the Comment Response

Document (see sectionSection XIX of this noticedocument).

2. Comments that Suggest the NRC Revisit Issues Associated with SFP Safety

These comments included suggestions that the NRC, as part of the MBDBE rule, should

reconsider SFP fires, events that can lead to SFP fires, malicious attacks involving SFPs, SFP

integrity during and following extreme events, and longer-term SFP aging issues. The

Commission has previously considered and dispositioned these issues, and the NRC concluded

that it was not within the scope of the MBDBE rule to revisit these SFP safety issues. Moreover,

the MBDBE rule is addressing and enhancing SFP safety through the imposition of regulations

that: 1) require licensees to have strategies that maintain or restore SFP cooling capabilities for

beyond-design-basis external events, and 2) provide information, through the use of SFPI, that

enables operators to appropriately prioritize the use of resources following a

beyond-design-basis external event. Explanations of the NRC’s considerations of the

commenters’ issues are provided as a convenience to stakeholders in the NRC response to

General Comment 8 in the Comment Response Document. (See sectionSection XIX of this

noticedocument.)

3. Comment Regarding Decommissioning

The NRC received comments from stakeholders that were directed towards the basis for

previous NRC exemption decisions regarding power reactor licensees in decommissioning.

While the MBDBE rule does include provisions that facilitate the reduction of its requirements at

the appropriate points within the decommissioning process, the rulemaking’s regulatory scope

does not include revisiting the bases for previous decisions on decommissioning exemptions.

64

Instead, the MBDBE rule is simply reflecting those decisions and enabling systematic removal

of the mitigation strategies requirements as a facility proceeds through the process of

decommissioning. The NRC enables these requirements to be removed through regulation,

rather than requiring removal by the more resource-intensive exemption process, based on the

same set of acceptance criteria that were used in granting the exemptions to licensees in

decommissioning. Concerns about the NRC’s decommissioning regulations should be raised in

the ongoing regulatory effort to more broadly address decommissioning issues for all applicable

requirements. (See “Regulatory Improvements for Decommissioning Power Reactors; Advance

notice of proposed rulemaking” (80 FR 72358; November 19, 2015).) If, as a result of that

regulatory effort, the NRC changes its position with regard to the bases for decommissioning

and, specifically, if those changes affect the decommissioning provisions that are part of the

MBDBE rule, then the NRC will make future conforming changes to the MBDBE rule to align it

with the revised decommissioning requirements.

4. Comments on Geomagnetic Disturbances

The NRC received comments on the subject of geomagnetic disturbances. While these

could be viewed as comments on a specific beyond-design-basis external event and be

addressed by the discussion in section IV.N.1, “Comments that Suggest a Completely Different

Approach to Mitigation of Beyond-Design-Basis Events,” of this notice, the NRC determined that

the issue warrants discussion given the NRC’s ongoing consideration of geomagnetic

disturbances. Although the MBDBE rule puts in place mitigation strategies that could be initially

deployed and used to address the effects of geomagnetic disturbances (should such

disturbances lead to adverse impacts on the transmission system and an associated loss-of-

offsite power), the rulemaking’s regulatory scope does not address the issue of geomagnetic

disturbances in its entirety. The impact of geomagnetic disturbances is the subject of

65

PRM-50-96, which the NRC accepted for consideration within its rulemaking process. The NRC

published this determination in the Federal Register on December 18, 2012 (77 FR 74788).

Accordingly, while not fully addressed within the MBDBE rule, the issue of geomagnetic

disturbances will be addressed as part of the NRC’s consideration of PRM-50-96, as discussed

in sectionSection III of this noticedocument.

V. Discussion

A. Rulemaking Objectives

The MBDBE rule accomplishes the following objectives: 1) makes the requirements in

the Mitigation Strategies and SFPI Orders generically applicable, giving consideration to lessons

learned from implementation of the orders and public comment on the MBDBE proposed rule; 2)

establishes new requirements for an integrated response capability; and 3and 2) addresses

issues raised by PRMs that were submitted to the NRC.

1. Makes the requirements in the Mitigation Strategies and SFPI Orders generically

applicable, giving consideration to lessons learned from implementation of the orders and public

comment on the MBDBE proposed rule.

This rule places the requirements in the Mitigation Strategies Order and SFPI Order into

the NRC’s regulations so that they apply to all current and future power reactor applicants, and

provides regulatory clarity and stability to power reactor licensees. In making the requirements

of the Mitigation Strategies Order generically applicable, this rule includes consideration of the

reevaluated hazard information developed in response to the March 12, 2012, NRC letter issued

under § 50.54(f) and ensures that licensees address the reevaluated hazard information within

66

their mitigation strategies. Because these orders were issued to then-current licensees, the

requirements of these orders would not apply to future licensees. and provides regulatory clarity

and stability to power reactor licensees. In the absence of this rule, these requirements would

need to be imposed on new reactor applicants or licensees through additional orders or license

conditions (as was done for all combined licenses (COLs) issued to date). As part of this

rulemaking, the NRC considered stakeholder feedback and lessons learned from the

implementation of the orders, including any challenges or unintended consequences associated

with implementation. The NRC reflected this stakeholder input in the final rule as discussed in

the previous section of this noticedocument as well as in regulatory guidance for this rule.

2. Establishes new requirements for an integrated response capability.

This rule establishes requirements for an integrated response capability for

beyond-design-basis events that integrates existing strategies and guidelines (implemented

through guideline sets) with the existing EOPs and enhances onsite emergency response

capabilities. This framework includes guideline sets for requirements that were formerly located

in § 50.54(hh)(2) and are now located in § 50.155(b)(3), as well as those for the Mitigation

Strategies Order. This framework also includes mitigation strategies, or alternative approaches,

used to address reevaluated hazards, as applicable. This rule requires sufficient staffing,

command and control, training, drills, communications capability, and documentation of changes

to support the integrated response capability.

3.2. Addresses a number of PRMs submitted to the NRC.

This rulemaking addresses, and completes the regulatory actions planned for, the five

PRMs filed by the NRDC that raise issues that pertain to the technical aspects of this

67

rulemaking. The petitions rely solely on the NTTF Report and request that the NRC undertake

rulemaking in a number of areas that are addressed by this rule. This rule also addresses, in

part, PRM-50-96 submitted by Mr. Thomas Popik; however, broader issues raised in that

petition regarding geomagnetic disturbances remain under consideration by the NRC.

B. Rulemaking Scope

The MBDBE rule addresses a significant number of regulatory issues that stem from

NRC review of the NTTF recommendations that provided the regulatory impetus for this rule,

including:

1. NTTF recommendations 4 and 7, and portions of NTTF recommendation 11.1

regarding onsite emergency resources to support multi-unit events with SBO, including the need

to deliver equipment to the site despite degraded offsite infrastructure. The implementation of

licensees’ responseresponses to these provisions of the MBDBE rule is largely complete,

because they were implemented under the Mitigation Strategies Order.

2. NTTF recommendation 8, and the command and control issues in NTTF

recommendation 10.2.

3. Numerous requirements regarding onsite emergency response actions

implemented by the Mitigation Strategies Order, including supporting guidance to implement the

emergency response aspects of this rule. The specific regulatory actions related to emergency

response in this rule and the associated NTTF recommendations arefollow:

a. Staffing and communications requirementsguidance that address NTTF

recommendation 9.3 and were also discussed in NTTF recommendations 9.1 and 9.2. These

regulatory issues were initially addressed throughin the implementation of the Mitigation

Strategies Order. through the regulatory guidance supporting the order. The regulatory

68

guidance for the MBDBE rule addresses supporting facilities and equipment, as discussed in

the same NTTF recommendations.

b. Training and exercise requirements and drill guidance that address NTTF

recommendation 9.3 and were also discussed in NTTF recommendations 9.1 and 9.2. These

regulatory issues were implemented under the Mitigation Strategies Order.

Accordingly, the MBDBE rule addresses NTTF recommendations 4, 7, 8, 9.1, 9.2, 9.3

(except for maintenance of ERDS capability throughout a beyond-design-basis external event),

10.2, and 11.1.

The MBDBE rule also addresses NTTF recommendation 9.4 to modernize ERDS. This

action differs from the other regulatory actions because ERDS is not an essential component of

a licensee’s capability to mitigate a beyond-design-basis external event. However, ERDS is an

important form of communication between the licensee and the NRC. Modernization of ERDS

was completed voluntarily by industry prior to issuance of this rule; therefore, NRC includes

amendments in this rule to remove the technology-specific references to outdated equipment in

10 CFR part 50, appendix E, section VI, “Emergency Response Data System.”

Severe Accident Management Guideline and Multiple Source Term Dose Assessment

The Commission considered a proposed SAMG backfit analysis, provided as part of

SECY-15-0065, “Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events

(RIN 3150-AJ49),” dated April 30, 2015. The Commission concluded that the imposition of

SAMG requirements was not warranted and, consequently, SAMGs were removed as

requirements in the MBDBE rule (refer to SRM-SECY-15-0065, dated August 27, 2015).

Instead, SAMGs continue to be implemented and maintained through an industry initiative. For

more information on the industry implementation of SAMGs, refer to the MBDBE proposed rule.

69

Multiple source term dose assessment requirements were part of the proposed MBDBE

rule and addressed NTTF recommendations 9.3 and 9.1. These proposed requirements are

removed in the final MBDBE rule and instead have been implemented by licensees as

discussed in Section IV.E, “Multiple Source Term Dose Assessment,” of this document.

Procedure and Guideline Integration

Procedure and guideline integration were part of the proposed MBDBE rule and

addressed NTTF recommendation 8. These proposed requirements are removed from the final

MBDBE rule and instead have been implemented by licensees as discussed in sectionSection

IV.E, “Multiple Source Term Dose AssessmentN, “Removal of Integration Requirements,” of this

noticedocument.

Scope of Procedure and Guideline Integration

The MBDBE rule limits the scope of the integrated response capability to the strategies,

guidelines, and alternative approaches under § 50.155(b). This rule includes:

Paragraph 50.155(b)(1). The MBDBE rule contains requirements that result from the

Mitigation Strategies Order and address beyond-design-basis external events (from natural

phenomena). These requirements are those that the NRC, while developing part of the

regulatory basis for this final rule, termed as “Station Blackout Mitigation Strategies.” The

nuclear industry refers to these as “FLEX Support Guidelines” (FSGs). The term FSGs,

therefore, is used in this notice to refer to the strategies and guidelines required by

§ 50.155(b)(1).

2. Paragraph 50.155(b)(2). The MBDBE rule contains requirements for reevaluated

seismic and flooding strategies and guidelines or alternative approaches in § 50.155(b)(2).

70

These strategies and guidelines or alternative approaches apply to licensees that have

reevaluated hazards that exceed in magnitude their design basis seismic and flooding external

event hazards. The phrase “exceed in magnitude” is discussed in section IV.C, “Reasonable

Protection,” and section VI of this notice. Depending on the particular design basis and

reevaluated external event hazards at each facility, these strategies and guidelines can be

identical to, similar to, or significantly different from those developed under § 50.155(b)(1).

Licensees may modify the strategies and guidelines required by § 50.155(b)(1) if the licensee

shows that the revised strategies and guidelines can address the effects of the reevaluated

hazards. The § 50.155(b)(2) strategies and guidelines can differ significantly from the

§ 50.155(b)(1) strategies and guidelines when the licensee chooses an alternative approach to

address the reevaluated hazard scenarios and associated damage states. This alternative may

use any available equipment (including the mitigation strategies equipment), as well as any

installed SSCs (including SSCs and equipment that were not part of mitigation strategies), as a

means to address the reevaluated hazard effects. The § 50.155(b)(2) strategies and guidelines

or alternative approaches differ from the strategies and guidelines in § 50.155(b)(1) and (3) in

an important manner when a licensee chooses to pursue an alternative approach. In such

cases, the MBDBE rule provides licensees the flexibility to develop strategies or alternative

approaches that address specific flooding and seismic scenarios and the associated effects on

the nuclear facility (whereas the guideline sets in § 50.155(b)(1) and (3) are intended to address

undefined, beyond-design-basis events).

3. Paragraph 50.155(b)(3) (formerly in § 50.54(hh)(2)). This paragraph addresses

the set of strategies and guidelines, referred to as EDMGs, that address the requirements in

former § 50.54(hh)(2) (now § 50.155(b)(3)). NEI 06-12, “B.5.b Phase 2 & 3 Submittal

Guideline,” Revision 2, defines EDMGs as a subset of the strategies and guidelines for

71

addressing the loss of large areas of the plant due to explosions or fire. NEI 06-12, Revision 2,

is endorsed in NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports

for Nuclear Power Plants: LWR Edition,” Section 19.4, “Strategies and Guidance to Address

Loss-of-Large Areas of the Plant Due to Explosions and Fires.” While the generic term

“EDMGs” in the final rule includes all of the strategies and guidelines used under § 50.155(b)(3),

this administrative change is not intended to expand or modify the requirements that are

associated with EDMGs or the loss of large areas of the plant due to explosions or fire.

The MBDBE rule’s integrated response capability structure avoids unnecessarily

revisiting the existing symptom-based EOPs that were developed following the Three Mile

Island, Unit 2 (TMI-2) accident. The NRC has determined that current regulations addressing

EOPs provide sufficient control of the EOPs. These requirements include the quality assurance

requirements of criterion V, “Instructions, Procedures, and Drawings,” and criterion VI,

“Document Control,” in appendix B, “Quality Assurance Criteria for Nuclear Power Plants and

Fuel Reprocessing Plants,” to 10 CFR part 50, and the administrative controls section of the

technical specifications for each plant. The NRC has also issued guidance for EOPs (e.g.,

NUREG-0660, “NRC Action Plan Developed as a Result of the TMI-2 Accident,” issued May

1980; NUREG-0737, “Clarification of TMI Action Plan Requirements,” issued November 1980;

and NUREG-0711, “Human Factors Engineering Program Review Model,” issued November

2012). In order to avoid the unnecessary regulatory burden that would result by moving the

requirements for EOPs into § 50.155 or requiring that the strategies, guidelines, and alternative

approaches of § 50.155(b) be integrated into the existing EOPs, § 50.155(b)(4) requires that the

strategies, guidelines, and alternative approaches of § 50.155(b) be integrated with the EOPs.

Guideline Sets Excluded From this Final Rule

72

During the development of this rule, other guideline sets were considered for inclusion

within the integrated response capability. The guideline sets considered included fire response

procedures, alarm response procedures, and abnormal operating procedures (AOPs). These

guideline sets were not included in the final rule for the reasons stated in section IV.B,

“Rulemaking Scope,” of the MBDBE proposed rule.

C. Final Rule Regulatory Bases

Applicability

This rule applies, in whole or in part, to applicants for and holders of an operating license

for a nuclear power reactor under 10 CFR part 50 or COL under 10 CFR part 52.

This rule does not apply to applicants for, or holders of, an operating license for a

non-power reactor under 10 CFR part 50, because non-power reactors pose lower radiological

risks to the public from accidents than power reactors. These reduced risks result from two

primary features of non-power reactors: 1) the core radionuclide inventories are lower than in

power reactors as a result of their lower power levels and often shorter operating cycle lengths;

and 2) non-power reactors have lower decay heat associated with a lower risk of core melt and

fission product release in a loss-of-coolant accident than power reactors.

A holder of a general or specific 10 CFR part 72 independent spent fuel storage

installation (ISFSI) license for dry cask storage is not subject to this rule for the ISFSI, because

the decay heat load of the irradiated fuel is sufficiently low prior to movement to dry cask

storage that it can be air-cooled. This situation would also meetsmeet the criteria for

“sunsetting,” or phased removal, of requirements (discussed later in this section of this

document).) if the rule were to apply to holders of such licenses.

73

The GE Morris facility in Illinois, which is the only SFP licensed under 10 CFR part 72 as

an ISFSI, does not need to comply with this rule and is excluded by the rule applicability

described in § 50.155(a). The NRC considered including the GE Morris facility within the scope

of this rule but found that the age and corresponding low decay heat load of the fuel in the

facility made it unnecessary. The GE Morris facility would also meetsmeet this rule’s sunsetting

criteria if the rule were to apply to GE Morris. While this rule leaves in force the EDMG

requirements of § 50.155(b)(3), those requirements are not applicable to GE Morris because it

is not a 10 CFR part 50 licensee. In the course of the development and implementation of the

guidance and strategies required by § 50.155(b)(3), the NRC evaluated whether additional

mitigation strategies were warranted at GE Morris and concluded that no mitigation strategies

were warranted beyond existing measures, due to the extended decay time since the last

criticality of the fuel stored there, the resulting low decay heat levels, and the assessment that a

gravity drain of the GE Morris SFP is not possible due to the low permeability of the surrounding

rock and the high level of upper strata groundwater.

Decommissioning reactors

The MBDBE rule contains a regulatory structure for phasing out the mitigation strategies

requirements for a licensee as its reactor decommissioning process proceeds. This structure

consists of three phases:

1. Once fuel is removed permanently from the reactor, the mitigation strategies

associated with the reactor and primary containment are no longer needed. Consequently, the

requirements of § 50.155 continue to apply, but only for the SFP.

2. When the decay heat of the spent fuel is reduced to a level that provides ample

time to enable ad hoc action to be taken in response to an event that can introduce kinetic

74

energy intoto sustain the SFP cooling function indefinitely, then all the requirements of § 50.155

can be removed with the exception of § 50.155(b)(32).

3. Once all fuel is removed from the SFP, all requirements of the MBDBE rule no

longer apply.

The following provides a more detailed discussion of this structure and the regulatory

decisions made for decommissioning licensees that provide the basis for this structure.

Once the NRC has docketed a licensee’sOnce a licensee has permanently ceased

operation, permanently removed fuel from the reactor vessel, and submitted the § 50.82(a)(1) or

§ 52.110(a) certifications of permanent cessation of operations and permanent removal of fuel

from the reactor vessel, that licensee need only comply with the requirements of § 50.155(b)

through (ed), and (gf) associated with maintaining or restoring SFP cooling. As discussed

previously, these proposed requirements are based on the Mitigation Strategies Order. The

licensees for the Kewaunee Power Station, Crystal River Unit 3 Nuclear Generating Plant, San

Onofre Nuclear Generating Station, Units 2 and 3, Fort Calhoun Station, and Vermont Yankee

Nuclear Power Station submitted § 50.82(a)(1) certifications after issuance of the Mitigation

Strategies Order. The NRC has rescindedwithdrawn the Mitigation Strategies Order for this

group of NPP licensees (Shutdown NPP Group).3 These rescissionswithdrawals were based on

the NRC’s conclusion that the lack of fuel in the licensee’s reactor core and the absence of

challenges to the containment rendered unnecessary the development of guidance and

strategies to maintain or restore core cooling and containment capabilities. Consistent with

these rescissionswithdrawals, the MBDBE rule relieves licensees in decommissioning from the

requirement to comply with the § 50.155(b) requirements to have mitigation strategies and

3 The Mitigation Strategies Order for Fort Calhoun Station, Unit 1, which has permanently ceased operations and

defueled, has not yet been rescinded, but the deadline for full compliance has been relaxed to August 31, 2017.

75

guidelines to maintain or restore core cooling and containment capabilities. Moreover, these

licensees do not need to comply with any of the other requirements in this final rule that support

compliance with the § 50.155(b) requirements to have mitigation strategies and guidelines for

maintaining or restoring core cooling and containment capabilities.

This MBDBE rule treats the EDMG requirements in a manner similar to the requirements

for FSGs.mitigation strategies developed under the Mitigation Strategies Order as made

generically applicable under § 50.155(b)(1). For a licensee that has submitted the § 50.82(a)(1)

or § 52.110(a) certifications docketed at the NRC, the lack of fuel in its reactor core and the

absence of challenges to the containment would render unnecessary EDMGs for core cooling

and containment capabilities. This licensee would not need to comply with the requirements in

the MBDBE rule associated with core cooling or containment capabilities; rather, the licensee

would be required to comply with the requirement to have EDMGs based on the presence of

fuel in the SFP.

Once the NRClicensee has docketed a licensee’ssubmitted the § 50.82(a)(1) or

§ 52.110(a) certifications, that licensee does not need to comply with the MBDBE requirement

in § 50.155(fe) that the licensee provide reliable means to remotely monitor wide-range SFP

levels to support effective prioritization of event mitigation and recovery actions. The

requirement in § 50.155(fe) makes generically applicable the requirements in the SFPI Order.

This order requires a reliable means of remotely monitoring wide-range SFP levels to support

effective prioritization of event mitigation and recovery actions in the event of a beyond-design-

basis external event with the potential to challenge both the reactor and SFP.

76

The NRC also rescindedwithdrew the SFPI Order for the Shutdown NPP Group.4 These

rescissionswithdrawals were based, in part, on the NRC’s conclusions that once a licensee

certifies the permanent removal of the fuel from its reactor vessel, the safety of the fuel in the

SFP becomes the primary safety function for site personnel. In the event of a challenge to the

safety of fuel stored in the SFP, decision makers would not have to prioritize actions and the

focus of the licensee staff would be the SFP condition. Therefore, once fuel is permanently

removed from the reactor vessel, the basis for the SFPI Order no longer applies. Consistent

with the NRC order rescissionswithdrawals, the NRC no longer requires licensees in

decommissioning to have a reliable means to remotely monitor wide-range SFP levels to

support effective prioritization of event mitigation and recovery actions in the event of a beyond-

design-basis external event with the potential to challenge both the reactor and SFP.

The Mitigation Strategies Order also required power reactor licensees to have certain

SFP cooling capabilities. In the rescissionwithdrawal letters to the licensees for the Shutdown

NPP Group, the NRC determined that, due to the passage of time, the fuel’s low decay heat,

and the long time to boil off the water inventory in the SFP obviated the need for the Shutdown

NPP Group licensees to have guidance and strategies necessary for compliance with the

Mitigation Strategies Order. The rescissionwithdrawal of the Mitigation Strategies Order for

those licensees eliminated the requirement for them to comply with the order’s requirements

concerning beyond-design-basis event strategies and guidelines for SFP cooling capabilities.

Consistent with the basis for the order rescissionswithdrawals, licensees in decommissioning

are relieved from the requirements concerning beyond-design-basis event strategies and

guidelines for SFP cooling capabilities and any related requirements. These licensees have to

4 On December 8, 2016, the NRC also rescinded the SFPI Order for Fort Calhoun Station, Unit 1, which has

permanently ceased operations and defueled.

77

perform and retain an analysis demonstrating that sufficient time has passed since the fuel

within the SFP was last irradiated, such that the fuel’s low decay heat and boil-off period provide

sufficient time for the licensee to obtain offsite resources to sustain the SFP cooling function

indefinitely. Licensees in decommissioning may use the equipment in place for EDMGs should

that equipment be available, recognizing that the protection for that equipment is against the

hazards posed by events that result in losses of large areas of the plant due to fires or

explosions rather than beyond-design-basis external events resulting from natural phenomena.

If the EDMG equipment is not available, offsite resources would be used by the licensee for

onsite emergency response (i.e., SFP cooling). This relief from the requirements related to the

Mitigation Strategies Order does not impact any commitments licensees have made to support

their requests for exemptions from offsite emergency planning requirements. The NRC’s

approval of such exemptions is based on the low radiological consequences of a beyond-

design-basis event in which a loss of SFP inventory could result in a zirconium cladding fire and,

conservatively, do not consider the ability to use offsite resources to mitigate such an event.

The NRC is maintaining the EDMG requirement for decommissioning plants because an

event for which EDMGs would be required is not based on the condition of the fuel, but may

instead result from an aircraft impact or a beyond-design-basis security event that could

introduce kinetic energyadditional heat into the SFP independent from the decay heat of the

fuel. These types of events and their potential consequences were considered as a part of the

final rule dated March 7, 2009, on Power Reactor Security Requirements (74 FR 13926). In the

course of that rulemaking, the NRC took into account stakeholder input and determined that it

would be inappropriate to apply the EDMG requirements to permanently shutdown and defueled

reactors where the fuel was removed from the site or moved to an ISFSI. However, the

resulting rule was written to removeinadvertently removed the EDMG requirements once the

78

certifications of permanent cessation of operations and removal of fuel from the reactor vessel

were submitted rather than upon removal of fuel from the SFP. The NRC is correcting this error

from the 2009 final rule in this final rule as explained in the “EDMGs” portion of this section.

The NRC is excluding from § 50.155 the licensee for Millstone Power Station, Unit 1,

Dominion Nuclear Connecticut, Inc. Dominion Nuclear Connecticut, Inc. is also the licensee for

Millstone Power Station, Units 2 and 3, but this exclusion applies to Dominion Nuclear

Connecticut, Inc. in its capacity as licensee for only Unit 1, which is not operating but has

irradiated fuel in its SFP and satisfies the proposed criteria for not having to comply with this

final rule except for the EDMG requirements. In the course of the development and

implementation of the guidance and strategies required by new § 50.155(b)(32), the NRC

evaluated whether additional mitigation strategies were warranted at Millstone Power Station,

Unit 1 and concluded that no mitigation strategies were warranted beyond existing measures.

This conclusion is based principally on the extended decay time since the last criticality

occurred on November 4, 1995, and the fact that this results in low decay heat levels that allow

sufficient time for the use of existing strategies. The exclusion for Millstone Power Station, Unit

1 in this rule is based upon that conclusion, with the understanding that additional mitigation

capabilities will be present because of the licensee’s implementation of the § 50.155(b)(32)

strategies at the collocatedco-located Millstone Power Station, Units 2 and 3.

Integrated Response Capability

Each applicant or licensee subject to the MBDBE rule is required to develop, implement,

and maintain an integrated response capability that includes FSGs, reevaluated hazards

strategies and guidelines or alternative approaches as applicable, EDMGs, sufficient staffing,

communications capabilities, and a supporting organizational structure with defined roles,

79

responsibilities, and authorities for directing and performing these strategies, guidelines, and

procedures. The MBDBE rule integrates this new capability with existing EOPs, as discussed in

further detail later in this section of the notice. The basis for this framework is explained in the

following discussion.

Mitigating Strategies for Beyond-Design-Basis External Events

The requirements in § 50.155(b)(1) for FSGs makesmitigating strategies make

generically applicable requirements previously imposed on licensees by the Mitigation

Strategies Order, as well as by license conditions included in the COLs held by Detroit Edison

Company (for Enrico Fermi Nuclear Plant, Unit 3), South Carolina Electric & Gas Company (for

Virgil C. Summer Nuclear Station, Units 2 and 3), Duke Energy Carolinas, LLC (for William

States Lee III Nuclear Station, Units 1 and 2), Dominion Virginia Power (for North Anna Power

Station, Unit 3),) and Florida Power &and Light Company (for Turkey Point, Units 6 and 7).5

The nuclear industry developed EDMGs following the terrorist events of September 11,

2001, in response to security advisories, orders, and license conditions issued by the NRC that

required licensees to develop and implement guidance and strategies intended to maintain or

restore core cooling and containment and SFP cooling capabilities under the circumstances

associated with the loss of large areas of the plant due to fire or explosion. The EDMGs further

extend the range of initiating events and plant damage states for which strategies and

guidelines are available for use by operators to include the loss of large areas of the plant and a

subsequent impairment of the operability and functionality of SSCs that are within that area.

The NEI 06-12, Revision 2 (the NRC-endorsed guidance for the requirements associated with

5 License No. NPF-95, condition 2.D(12)(g); License No. NPF-93, condition 2.D(13) and License No. NPF-94,

condition 2.D(13); License No. NPF-101, condition 2.D(12)(j) and License No. NPF-102, condition 2.D(12)(j); and License No. NPF-103, condition 2.D(12)(f);) and License No. NPF-104, condition 2.D(12)(h) and License No. NPF-105, condition 2.D(12)(h).

80

EDMGs), provides appropriate coordination of the EDMGs with the SAMGs through its guidance

that the EDMGs “must be interfaced with existing SAMGs so that potential competing

considerations associated with implementing these and other strategies are appropriately

addressed.”

Based upon these considerations, the NTTF recommended that the NRC require

licensees to further integrate EOPs, SAMGs and EDMGs, including a clarification of transition

points, command and control, decision making, and rigorous training that includes conditions

that are as close to real accident conditions as feasible.

Based on the lessons learned from the Fukushima Dai-ichi event, the range of initiating

events and plant damage states for which strategies and guidelines are available for use by

operators was further extended through the development of mitigation strategies for beyond-

design-basis external events in response to the Mitigation Strategies Order. The development

and implementation of this set of strategies and guidelines was accomplished giving

consideration to other NTTF recommendations to the extent practical. In order to provide better

integration with the EOPs, the FSGs leave the designation of command and control and

decision making functions within the EOPs or SAMGs, as appropriate. Consistent with the

recommendation in the NTTF Report, this rule requires that EDMGs and FSGs, including

strategies and guidelines or alternative approaches, as applicable, for reevaluated hazards, be

integrated with EOPs. This maintains EOPs as the central element of a licensee’s initial

response capability.

In establishing a requirement for an integrated response capability, the NRC considered

the fact that these strategies, guidelines, and procedures were developed at separate times

over a period of several decades and that the associated efforts have been focused on

responding to different types of initiating events and plant damage states. As a result, these

81

strategies, guidelines, and procedures may not properly reflect consideration of the interfaces

(e.g., procedure transitions), dependencies (e.g., reliance on common systems or resources)

and interactions (e.g., alignment of response strategies) among strategies, guidelines, and

procedures that may be used in combination, either consecutively or concurrently, to mitigate a

design-basis or beyond-design-basis event.

Additionally, the NRC considered that these strategies, guidelines, and procedures are

not used by a single licensee organizational unit but will often require coordination and transfer

of responsibilities among licensee organizational units. For example, in the event of the loss of

the main control room, the EDMGs may be implemented, and therefore initiated and directed by

knowledgeable and available site personnel until coordination and augmentation efforts enable

transition to a more stable command and control structure. The mitigation strategies for

beyond-design-basis external events, though initiated by the main control room complement of

licensed operators, may require coordination with and augmentation by offsite organizations.

Further, and as noted previously, there are potential accident scenarios in which a licensee

might employ strategies from more than one of these strategies, guidelines, and procedures

during its response to an accident. One plausible sequence is for operators to take initial action

using the EOPs, supplement these actions with actions under the FSGs, and ultimately

transition to actions under the SAMGs. Such an accident progression engages and requires the

coordination of multiple licensee organizational units.

In light of the preceding considerations, this MBDBE rule requires that the mitigation

strategies, guidelines, and procedures, staffing, and supporting organizational structure be

developed, implemented, and maintained such that they function as an “integrated” response

capability. The intent of this integrated response capability requirement is to ensure that

applicants and licensees establish and maintain a functional capability to produce a coordinated

82

and logical response under a wide range of accident conditions. The intent is not to require

physical integration (e.g., organizations need not be merged and strategies, guidelines, and

procedures need not be combined), but rather to require a functional integration of the elements

of the response capability.

To achieve this functional integration, the NRC expects that applicants and licensees

have addressed the interfaces, dependencies, and interactions among the elements of their

response capability. For example, functional integration of the strategies, guidelines, and

procedures would ensure that transition points are explicitly identified and conflicts between

strategies are eliminated to the extent practical. Functional integration of response

organizations ensures that organizations working together to use these strategies, guidelines,

and procedures (e.g., to coordinate actions or provide support) have clearly defined lines of

communication among the organizations, as well as clearly defined authorities and

responsibilities relative to each other, such that there are no gaps or conflicts.

Assumed Damage State for Development of the Strategies and Guidelines

Recognizing that beyond-design-basis external events are fundamentally unbounded,

and that these events can result in a multitude of damage states and associated accident

conditions, a significant regulatory challenge is developing bounded requirements that

meaningfully address the regulatory issue. From a practical standpoint, development of

mitigation strategies requires that there be a reasonable definition (or boundary conditions

established) for an onsite damage state that the strategies would then address and thereby

provide an additional capability to mitigate beyond-design-basis external event conditions that

might occur. The assumed damage state should ideally capture a reasonable range of potential

damage states that might occur as a result of beyond-design-basis external events, and it

83

should present an immediate challenge to the key safety functions for the facilities, so that the

resultant strategies provide greater capabilities and can improve safety. An assumed damage

state that accomplishes this objective is the loss of all ac power.

The MBDBE rule and the Mitigation Strategies Order both require the mitigation of a loss

of all ac power condition. Both the MBDBE rule and the Mitigation Strategies Order address this

requirement in two parts: 1) through an assumed damage stage that is used to develop the

strategies and guidelines for the mitigation of beyond-design-basis external events, and 2)

through supporting contingencies within the strategies that address conditions that are more

severe than those assumed to develop the strategies and guidelines. The assumed damage

state for this rule is the same as that assumed to implement the requirements of attachment 2 to

the Mitigation Strategies Order for currently operating power reactors: a loss of all ac power

condition concurrent with an LUHS. This assumed damage state is effective at immediately

challenging the key safety functions of core cooling, containment, and SFP cooling following a

beyond-design-basis external event. Requiring strategies to maintain or restore these key

functions under such circumstances results in an additional mitigation capability consistent with

the Commission’s objective when it issued the Mitigation Strategies Order.

As discussed in sectionSection IV.D, “Loss of All Alternating Current Power,” of this

noticedocument, the public comments provided on the MBDBE proposed rule showed some

confusion regarding the requirement for loss of all ac power. The proposed rule contained the

language “extended loss of all ac power.” The requirements in § 50.155(b)(1) provide for a

capability to maintain or restore key functional capabilities indefinitely, or until sufficient site

functional capabilities can be maintained without the need for mitigation strategies. As such, the

word “extended” was unnecessary, and the NRC deleted it to reduce confusion with the “ELAP”

term used in industry guidance; implementation of the requirements in § 50.155(b)(1) involves

84

the use of contingencies that address damage states more severe than an assumed ELAP.

Together, therefore, the assumed ELAP and the contingencies are the means for meeting a loss

of all ac power requirement.

This MBDBE rule is not prescriptive in terms of the specific set of initial and boundary

conditions assumed for the loss of all ac power and LUHS condition. The damage state for

currently operating reactors, defined in more detail in RG 1.226, reflects currently operating

power reactor designs and the reliance of those designs on ac power, while the assumed

damage state for a future design may be different depending upon the design features.

Specifically, the damage state of a loss of all ac power condition concurrent with an LUHS in the

Mitigation Strategies Order was implemented first through the assumption of an ELAP, while

allowing ac power from the inverters to be assumed available. This assumption is used to

establish event sequence and the associated times for when mitigation actions would be

assumed to be required. Secondly, to address the MBDBE rule and the Mitigation Strategies

Order requirement for a loss of all ac power, including ac power from the batteries (through

inverters), contingencies are included in the mitigation strategies to enable actions to be taken

under those circumstances (e.g., sending operators to immediately take manual control over a

non ac-powered core cooling pump). As such, this provision makes generically applicable the

current implementation under the Mitigation Strategies Order with no intent to either relax or

impose new requirements, and is performance-based to allow some flexibility for future designs.

As an example, some reactor designs (e.g., Westinghouse AP1000 and General Electric

Economic Simplified Boiling Water Reactor (ESBWR)) use passive safety systems to meet NRC

requirements for maintaining key safety functions. The inherent design of those passive safety

systems makes certain assumptions, such as LUHS, not credible.inappropriate. Accordingly,

the assumed condition for the FSGmitigation strategies requirements for passive reactors is the

85

loss of normal access to the normal heat sink, discussed further in this section. Nevertheless, in

this rule the NRC is requiring that the strategies and guidelines be capable of implementation

during a loss of all ac power.

Regarding the assumed LUHS for COLs or applications referencing the AP1000 or the

ESBWR designs, the assumption was modified to be a loss of normal access to the normal heat

sink (see, e.g., attachment 3 to the Mitigation Strategies Order; the Virgil C. Summer Nuclear

Station, Unit 2 license, License No. NPF-93, condition 2.D(13); and the Enrico Fermi Nuclear

Plant, Unit 3 license, License No. NPF-95, condition 2.D(12)(g)). This modified language

reflects the passive design features of the AP1000 and the ESBWR that provide core cooling,

containment, and spent fuel cooling capabilities for 72 hours without reliance on ac power.

These features do not rely on access to any external water sources for the first 72 hours

because the containment vessel and the passive containment cooling system serve as the

safety-related ultimate heat sink for the AP1000 design and the isolation condenser system

serves as the safety-related ultimate heat sink for the ESBWR design.

As discussed previously, the range of beyond-design-basis external events is

unbounded. The MBDBE rule is not intended, and should not be understood, to mean that the

mitigation strategies can adequately address all postulated beyond-design-basis external

events. It is always possible to postulate a more severe event that causes greater damage and

for which the mitigation strategies may not be able to maintain or restore the functional

capabilities (e.g., meteorite impact). Instead, the MBDBE requirements provide additional

mitigation capability in light of uncertainties associated with external events, consistent with the

NRC’s regulatory objective for issuance of the Mitigation Strategies Order.

The MBDBE rule requires that the FSGsmitigating strategies for beyond-design-basis

external events in § 50.155(b)(1) be capable of being implemented site-wide. This recognizes

86

that severe external events are likely to impact the entire reactor site, and for multi-unit sites,

damage all the power reactor units on the site. This requirement means that there needs to be

sufficient equipment and supporting staff to enable the maintenance or restoration of core

cooling, containment, and SFP cooling functions for all the power reactor units on the site. This

is a distinguishing characteristic of this set of mitigation strategies from those in § 50.155(b)(32),

for which the damage state is a more limited, albeit large area of a single plant, reflecting the

hazards for which that set of strategies was developed.

The NRC gave consideration to whether there should be changes made to § 50.63 (the

Station Blackout Rule) to link those requirements with this rule. This consideration stemmed

from recommendation 4.1 of the NTTF Report to “initiate rulemaking to revise 10 CFR 50.63”

and the understanding that this rule could result in an increased SBO coping capability, in

addition to the regulatory objectives of the MBDBE rule, which provide additional beyond-

design-basis external event mitigation. Because of the substantive differences between the

requirements of § 50.63 for licensees to be able to withstand and recover from an SBO and the

MBDBE requirements, the NRC determined that such a linkage is not necessary and could lead

to regulatory confusion.

The principal regulatory objective of § 50.63 was to establish SBO coping durations for a

specific scenario: the loss of offsite power coincident with a failure of all trains of emergency

onsite ac power (typically, the failure of multiple emergency diesel generators). In meeting this

regulatory objective, the NRC understood that there would be safety benefits accrued through

the provision of an alternate ac source diverse from the emergency diesel generators and

therefore defined “alternate ac source” in § 50.2. The NRC defined the event a licensee must

withstand and recover from as a “station blackout” rather than a “loss of all ac power.” An SBO

allows for continued availability of ac power to buses fed by station batteries through inverters or

87

by alternate ac sources. The MBDBE rule requires an additional capability to mitigate

beyond-design-basis external events. Because the condition assumed for the mitigation

strategies to establish the additional mitigation capability includes ana loss of all ac power,

which is more conservative than an SBO as defined in § 50.2 (because it covers an indefinite

period, not a loss for a certain amount of time, and it also assumes the loss of alternate ac

sources), there can be a direct relationship between the two different sets of requirements with

regard to the actual implementation at the facility. Specifically, implementation of the mitigation

strategies links into the SBO procedures (e.g., the applicable strategies would be implemented

to maintain or restore the key safety functions when the EOPs reach a “response not obtained”

juncture).6

Step-by-step procedures are not necessary for many aspects of the mitigation strategies

and guidelines. Rather, the strategies and guidelines are intended to be flexible, and enable

plant personnel to adapt them to the conditions that result from the beyond-design-basis

external event. The provisions typically would result in strategies and guidelines that use both

installed and portable equipment, instead of only relying on installed ac power sources (with the

exception of protected battery power) to maintain or restore core cooling, containment, and SFP

cooling capabilities. By using equipment that is separate from the normal installed ac-powered

equipment, the strategies and guidelines have a diverse attribute. By having available multiple

sets of portable equipment that can be deployed and used in multiple ways depending on the

circumstances of the event, operators are able to implement strategies and guidelines that are

flexible and adaptable.

6 One of the formats for symptom-based EOPs that are used in the operating power reactors has the operators

take an action and verify that the system responds to the action in a manner that confirms that the action was effective. For example, a step in an EOP could be to open a valve in order to allow cooling water flow, and the verification would be obtained by confirming there are indications that flow has commenced, such as a decrease in temperature of the system being cooled. If those indications are not obtained, the procedure would provide instructions on the next step to accomplish in a separate column labeled “response not obtained.”

88

The mitigation strategies requirements are both performance-based and functionally-

based. The performance-based requirements recognize that the new requirements provide

most benefit to future reactors whose designs could differ significantly from current power

reactor designs and as such, use of more prescriptive requirements could be problematic and

create unnecessary regulatory impact and need for exemptions. Use of functionally-based

requirements results from the need to have requirements that can address a wide range of

damage states that might exist following beyond-design-basis external events. Maintaining or

restoring three key functions (core cooling, containment, and SFP cooling) supports

maintenance of the fission product barriers (i.e., fuel clad, reactor coolant pressure boundary,

and containment) and results in an effective means to mitigate these events, while remaining

flexible such that the strategies and guidelines can be adapted to the damage state that occurs.

Functionally-based requirements also result in strategies that align well with the symptom-based

procedures used by power reactors to respond to accidents. Accordingly, the Mitigation

Strategies Order contained requirements for a three-phased approach for current operating

reactors. The MBDBE rule does not specify a number of phases; instead, it establishes higher-

level, performance-based requirements consistent with this discussion. Section IV.K,

“Consideration of Explicit Requirements for a Three-Phase Response,” of this noticedocument

contains further discussion of this aspect of the MBDBE rule.

The NRC considered incorporating into this rule a requirement that licensees be capable

of implementing the strategies and guidelines “whenever there is irradiated fuel in the reactor

vessel or spent fuel pool.” This provision would have been a means of making generically

applicable the requirement from the Mitigation Strategies Order that licensees be capable of

implementing the strategies and guidelines “in all modes.” The NRC considered the terminology

“whenever there is irradiated fuel in the reactor vessel or spent fuel pool” to be a better means

89

to address the order requirement because the phrase did not use technical specification type

language (i.e., modes), which is in effect when a licensee completely offloads the fuel from the

reactor vessel into the SFP during an outage. The NRC did not use the phrases, “whenever

there is irradiated fuel in the reactor vessel or spent fuel pool,” or, “in all modes,” in the MBDBE

rule and instead structured the applicability provisions to achieve this same objective by

requiring licensees to have mitigation strategies for beyond-design-basis external events for the

various configurations that can exist for the reactor and SFPs throughout the operational,

refueling, and decommissioning phases.

The mitigation strategies and guidelines implemented under the Mitigation Strategies

Order assume a demanding condition that maximizes decay heat that would need to be

removed from the reactor core and SFP source terms on site. This implementation results in a

more restrictive timeline (i.e., mitigation actions required earlier following the event to take

actionsooner to maintain or restore cooling to these source terms) and a greater resulting

additional capability. These assumed at-power conditions are 100 days at 100 percent power

prior to the occurrence of the beyond-design-basis event for the reactor core, consistent with the

assumption used for § 50.63. This assumption establishes a conservative decay heat for the

reactor source term. The assumed SFP conditions include the design basis heat load for the

SFP, which is typically a full core offload following a refueling outage which, as the heat load

that is used for the sizing of FLEX equipment. For the purposes of determining the response

time for the SFP strategies when fuel is in the reactor vessel, the rate of inventory loss of the

SFP is calculated based on the worst case conditions for SFP heat load assuming the plant is at

power. The NRC considers the development of timelines for the mitigation strategies using

these assumptions for the reactor core and SFP to be appropriate.

90

The NRC recognizes the difficulty of developing engineered strategies for the

extraordinarily large number of possible plant and equipment configurations that might exist

under shutdown conditions (i.e., at shutdown when equipment may be removed from service,

when there is ongoing maintenance and repairs or refueling operations, or modifications are

being implemented). Licensees must be cognizant of such configurations, equipment

availability, and decay heat states that could present greater challenges under these conditions,

and design mitigation strategies that can be implemented under such circumstances.

The NRC considered incorporating requirements into the MBDBE rule that would require

strategies to be developed that specifically assume that delays in the receipt of offsite resources

occur as a result of damage to the transportation infrastructure. While severe events could

damage local infrastructure, and could create challenges with regard to the delivery of offsite

resources, the NRC concluded that having this level of specificity in the MBDBE rule is not

necessary. Instead, this rule contains provisions that are more performance-based, requiring

continued maintenance or restoration of the functional capabilities until acquisition of offsite

assistance and resources. Potential delays and other challenges presented by extreme events

that affect acquisition and use of offsite resources are addressed by licensee programs that

implement the provisions of this rule.

The Mitigation Strategies Order included a requirement that licensees develop guidance

and strategies to obtain “sufficient offsite resources to sustain [the functions of core cooling,

containment, and SFP cooling] indefinitely.” The NRC considered using this language in this

rule, but concluded that this would be better phrased as “indefinitely, or until sufficient site

functional capabilities can be maintained without the need for the mitigation strategies.” The

NRC concluded that this phrase more clearly communicates the existence of a transition from

the use of the mitigation strategies to recovery operations.

91

The NRC recognizes that the use of the mitigation strategies potentially requires

departure from a license condition or a technical specification (contained in a license issued

under 10 CFR part 50 or 52) and could be considered a proceduralization of the allowance

provided under § 50.54(x). Given that the initiation of the use of these strategies may be

included in EOPs or other procedures, which might be considered procedures described in the

final safety analysis report (as updated), there is an interaction with the provisions of

§ 50.59(c)(1) regarding the need to obtain a license amendment in order to make the necessary

change to those procedures. The NRC considered including provisions in this rule specifically

to allow departures from license conditions or technical specifications in order to clarify this

situation, but found these provisions unnecessary. For holders of operating licenses under

10 CFR part 50 and COLs under 10 CFR part 52 that were subject to the Mitigation Strategies

Order, the provisions of that order provided more specific criteria for making the necessary

changes than § 50.59, making that section inapplicable as set forth in § 50.59(c)(4). Those

criteria included the provision of submitting an overall integrated plan to the NRC for review.

Similar criteria were included in license conditions for the subsequently issued COLs.

92

EDMGs

In support of the regulatory objective to require licensees to have an integrated response

capability, and recognizing the recognition of the similarity of the existing EDMGs formerly in

§ 50.54(hh)(2) to the FSGsstrategies required by § 50.155(b)(1), the NRC relocated the EDMGs

into the MBDBE rule as § 50.155(b)(32). In addition to moving the text, the NRC made a few

editorial changes. The wording used to describe these requirements has evolved from

“guidance and strategies,” in Order EA-02-026, “Interim Safeguards and Security Compensatory

Measures,” dated February 25, 2002, to “strategies,” in the corresponding license conditions, to

“guidance and strategies,” in § 50.54(hh)(2), to its current form, “strategies and guidelines.” The

word “guidelines” was chosen rather than “guidance” to more accurately reflect the nature of the

instructions that a licensee could develop and to avoid confusion with the term “regulatory

guidance.” The word “strategies” is used in this rule to reflect its meaning, “plans of action.”

The resulting plans of action may include plant procedures, methods, or other guideline

documents, as deemed appropriate by the licensee during the development of these strategies.

These plans of action also include the arrangements made with offsite responders for support

during an actual event. No substantive change to the requirements is intended by this change

in the wording.

The final rule clarifies the § 50.155(b)(32) requirements by adding the phrase “impacted

by the event” in order to differentiate these requirements from those located in § 50.155(b)(1).

The requirements in § 50.155(b)(32), which address the loss of large areas of the plant, are

limited to the areas of the plant impacted by the event, and as such, are not intended to address

a site-wide event. This clarification was necessary as a result of the relocation of these

requirements to the MBDBE rule and their juxtaposition with the mitigation strategies for

beyond-design-basis external events in § 50.155(b)(1), which are for a site-wide event. The

93

events for which EDMGs would be used can impact key equipment that is shared between

power reactor units (i.e., SFPs), and that is why the NRC did not use language that would have

limited the application of these requirements to an individual power reactor unit. This

clarification is to preserve the scope of this requirement, and specifically avoid an unintended

imposition of a new requirement.

Applicability of the requirements of § 50.155(b)(32) was formerly governed by

§ 50.54(hh)(3), which made these requirements inapplicable following the submittal of the

certifications required under § 50.82(a) or § 52.110(a)(1). As discussed in the Power Reactor

Security Requirements final rule, the NRC concludes that it is inappropriate for the requirements

for EDMGs to apply to a permanently shutdown, defueled reactor, where the fuel was removed

from the site or moved to an ISFSI. The NRC is requiring EDMGs for a licensee with

permanently shutdown defueled reactors, but with irradiated fuel still in its SFP, because the

licensee must be able to implement effective mitigation measures for large fires and explosions

that could impact the SFP while it contains irradiated fuel. The MBDBE rule corrects the

wording of former § 50.54(hh)(3) to implement the sunsetting of the associated requirement as

intended by the Commission in 2009. This change does not constitute backfitting for currently

operating reactors because the change concerns decommissioning reactors. The change does

not constitute backfitting for (except Watts Bar Nuclear Plant, Unit 2), current COL holders, and

currently decommissioning reactors with spent irradiated fuel in their SFP (except Millstone

Power Station, Unit 1, as it is not subject to 10 CFR 50.155) because the EDMGs are also

required by the licensees’licensee’s license conditions that were made generically applicable

through. Watts Bar Nuclear Plant, Unit 2, does not have the license condition, but TVA has

consented to the Power Reactor Security Requirements rulemakingimposition of this

requirement without the NRC conducting a backfit analysis for this imposition on Watts Bar

94

Nuclear Plant, Unit 2. The NRC request for TVA’s consent and TVA’s response are referenced

in Section XIX, “Availability of Documents,” of this document. The MBDBE rule replaces the

license conditions on the effective date of the MBDBE rule, thereby maintaining the EDMG

requirement for these licensees.

In the proposed MBDBE rule, the NRC discussed secondary containment aspects of the

mitigation strategies in the decommissioning provisions of § 50.155(a) for licensees that rely on

secondary containment as a fission product barrier for their SFPs. The intent of the proposed

requirement was to document the requirement without changing the requirements that had been

imposed under the Mitigation Strategies Order and § 50.54(hh)(2). In the course of interactions

with the ACRS and during the CER meeting, the NRC received feedback that this phrasing of

the requirement was confusing and conveyed that the requirements were being modified..

Therefore, the NRC has revised the final MBDBE rule to eliminate the discussion of secondary

containment in the decommissioning provisions of § 50.155(a).

Integration with EOPs

In developing a requirement for the integration of strategies, guidelines, and alternative

approaches of § 50.155(b) with the EOPs, the NRC considered their differences in content and

the standards for usage applied to them. The EOPs are a specific and prescribed set of

instructions implemented following exacting standards for usage and adherence (e.g., step-by-

step sequential performance, concurrent execution of multiple sections) that operators and plant

staff are required to follow when performing a specific task or addressing plant conditions.

When licensees implement procedures, each step is to be performed as prescribed, with rare

exceptions. The strategies and guidelines that are required by the MBDBE rule differ from

EOPs primarily in terms of the level of detail to which they are written and expectations

95

regarding usage. The MBDBE strategies and guidelines may be a less prescriptive set of

instructions than the EOPs and may not be subject to the same constraints imposed by

standards of usage for procedure implementation (e.g., may not be followed in a step-by-step

manner). This is because the MBDBE strategies and guidelines must take into account: 1) the

large number of possible event initiators, plant configurations, and sequences; and 2) the high

degree of uncertainties in event progression and consequences. The strategies and guidelines

can take the form of high level plans that identify and describe potential, previously evaluated,

success paths for addressing specific conditions such as loss of core cooling. As a result,

strategies and guidelines provide operators and plant staff the information and latitude to

respond as necessary to unpredictable and dynamic situations, allowing them to adapt to the

actual conditions and damage states without the burden of detailed procedures and the

challenge of determining which procedure may be applicable and effective under the uncertain

conditions of a beyond-design-basis event.

Given these differences in content and standards for usage, the intent of this rule is not

to require conformance of the strategies and guidelines to the level of detail and standards of

usage for EOPs, or consolidation of the strategies, guidelines, and procedures into a single set

of instructions, but rather, as previously described, to require functional integration of strategies

and guidelines with the EOPs. The objective is for the strategies, guidelines, and procedures to

retain or employ the characteristics that support their effective use under the range of conditions

to which they are each intended to apply while ensuring that the strategies and guidelines, in

conjunction with the EOPs, constitute a useable and cohesive set of instructions for mitigating

the consequences of a wide range of initiating events and plant damage states. To achieve this

functional integration, the NRC expects that applicants and licensees will address the interfaces,

dependencies, and interactions among the strategies and guidelines that are required under this

96

rule and the EOPs, such that they can be implemented in concert with each other, as

necessary, to effectively use available plant resources and direct a logical and coordinated

response to a wide range of accident conditions.

In keeping with the basis for a functional integration of the strategies and guidelines with

EOPs, the MBDBE rule requires that the § 50.155(b) strategies, guidelines, and alternative

approaches be integrated “with the Emergency Operating Procedures (EOPs).” This language

is intended to communicate the NRC’s expectation that the EOPs retain their role as the primary

means of directing emergency operations and that the strategies and guidelines that are

required under this rule are integrated with EOPs to support their implementation.

The NRC considered establishing specific criteria for the integration of the strategies and

guidelines with EOPs that supports a capability to mitigate beyond-design-basis events but

opted to specify only a high level requirement to allow applicants and licensees flexibility in the

means by which they achieve the functional integration described previously. Approaches for

achieving functional integration could include the following:

1. Strategies, guidelines, and procedures have clearly defined transitions (e.g., entry

and exit conditions with distinct pointers) from one strategy, guideline, or procedure to another.

2. Individuals are cued by the document or trained to know when transitions between

the strategies, guidelines, and procedures result in corresponding changes in the associated

standards for usage (e.g., when transitioning from EOPs to the SAMGs, the operator is able to

recognize the transition from a step-by-step procedure to a flexible guideline set where it is

permissible to deviate from the order or method of accomplishing the steps).

3. Licensees establish expectations (e.g., through standards for usage) pertaining to the

parallel use of strategies, guidelines, and procedures. Plant personnel using different

97

strategies, guidelines, and procedures concurrently understand which is the controlling

procedure and therefore which actions take precedence.

4. Licensees identify and resolve conflicts between the strategies, guidelines, and

procedures.

5. Licensees identify competing considerations when using the strategies, guidelines,

and procedures and eliminate or address them in guidance.

6. Licensees control the development and maintenance of their content and format

using human factors standards and guidelines (e.g., writer’s guides) that recognize and address

the interfaces between them in order to achieve compatibility of the strategies, guidelines, and

procedures.

Staffing

The MBDBE rule requires that licensees provide the staffing necessary for having an

integrated response capability to support implementation of the strategies, guidelines, and

alternative approaches required by § 50.155(b). To be effective, staffing for an expanded

response capability should include the trained and qualified individuals who would be relied

upon to analyze, recommend, authorize, and implement the mitigation strategies. The staffing

required of a licensee by the MBDBE rule is that staffing necessary to directly support the

assessment and implementation of the range of mitigation strategies developed, implemented,

and maintained by the license that are intended to maintain or restore the functions of core

cooling, containment, and SFP cooling.

The recommended minimum positions and staffing levels for emergency plans were

initially provided in 1980 in NUREG-0654/FEMA-REP-1, “Criteria for Preparation and Evaluation

of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power

98

Plants,” Revision 1. In 2011, the NRC issued the “Enhancements to Emergency Preparedness

Regulations” final rule (Emergency Preparedness final rule) (76 FR 72560; November 23, 2011)

to amend, in part, 10 CFR part 50, appendix E, to address concerns about the assignment of

tasks or responsibilities to on-shift emergency response organization (ERO) personnel that

would potentially overburden them and prevent the timely performance of their functions under

the emergency plan. Licensees must have enough on-shift staff to perform specified tasks in

various functional areas of emergency response 24 hours a day, 7 days a week. The MBDBE

rule addresses the staffing requirements for the expanded response capabilities for on-shift

response and the ERO.

The MBDBE rule requires adequate staffing to implement the strategies, guidelines, and

alternative approaches required by § 50.155(b) with the EOPs without requiring further analysis

to supplement analyses that were completed as a result of the Mitigation Strategies Order or the

Emergency Preparedness final rule. Staffing levels should be established to ensure that if

strategies are executed, completing them would not be delayed due to the lack of qualified

personnel. The MBDBE rule contains drill and training requirements that provide assurance that

the licensee staff are properly trained and can demonstrate implementation of the mitigation

strategies and guidelines. These additional requirements also provide assurance that licensees

maintain sufficient staffing levels, because insufficient staffing levels would result in ineffective

implementation of the strategies.

Command and Control

The MBDBE rule requires licensees to have a supporting organizational structure with

defined roles, responsibilities, and authorities for directing and performing the strategies,

guidelines, and alternative approaches required by § 50.155(b). The objective is to ensure that

99

licensees address the organizational implications of: 1) implementing the FSGs; and 2)

integrating the FSGs, reevaluated hazard strategies and guidelines or alternative approaches,

and EDMGs with the EOPs such that organizational units responsible for on-site accident

mitigation (e.g., main control room, emergency operations facility, and technical support center

staff) can support a coordinated implementation of these procedures and guidelines under the

challenging conditions presented by beyond-design-basis events.

Additional requirements exist in 10 CFR part 50, appendix E, section IV.A,

“Organization,” for the inclusion within the licensee’s emergency plan of a description of the

organization for coping with radiological emergencies, including definition of authorities,

responsibilities, and duties of individuals assigned to the licensee’s emergency organization and

the means for notification of such individuals in the event of an emergency. These requirements

provide the command and control structure for use in the execution of the emergency plan. The

current 10 CFR part 50, appendix E, sections IV.A.2. and IV.A.5., further require that the

emergency plan include: 1) a detailed description of the authorities, responsibilities, and duties

of the individual(s) who will take charge during an emergency; 2) plant staff emergency

assignments; 3) authorities, responsibilities, and duties of an onsite emergency coordinator who

shall be in charge of the exchange of information with offsite authorities responsible for

coordinating and implementing offsite emergency measures; and 4) the identification, by

position and function to be performed, of other employees of the licensee with special

qualifications for coping with emergency conditions that may arise.

The need for defined command and control structures and responsibilities for use in

beyond-design-basis conditions was recognized in the course of the development of the

guidance and strategies for the former § 50.54(hh)(2), now § 50.155(b)(3). As stated in the

industry’s guidance document for that set of requirements, NEI 06-12, Revision 2, “[e]xperience

100

with large scale incidents has shown that command and control execution can be a key factor to

mitigation success.” The guidance and strategies developed for that effort include an EDMG for

initial response to provide a bridge between normal operational command and control and the

command and control that is provided by the ERO in the event that the normal command and

control structure is disabled. The NRC considers that the actions taken in the development of

the EDMGs for initial response for the guidance and strategies for § 50.155(b)(3) continue to be

adequate for compliance with the MBDBE rule for EDMGs.

The regulatory guidance for the MBDBE rule, specifically RG 1.226, which endorses

industry guidance in NEI 12-06, specifies that the existing command and control structure will be

used for transition to the SAMGs.

All previous requirements did not specify a command and control structure for a

multi-unit event that includes the potential need for acquisition of offsite assistance to support

onsite event mitigation. Additionally, these requirements were not understood to require such a

response because they preceded the Fukushima Dai-ichi event and the regulatory actions that

stemmed from that event. As a practical matter, the current command and control structures,

including any changes that resulted from the implementation of the Mitigation Strategies Order

requirements, are sufficient to ensure that the functional objectives of the MBDBE rule are

achieved. The NRC requested stakeholder feedback on this issue in the proposed rule (refer to

section VI, “Specific Requests for Comments,” of the proposed rule Federal Register notice).

Based on that feedback, which suggested that the MBDBE rule should contain its own

command and control requirements, the NRC has concluded that it is appropriate to require

command and control for the integrated response capability in the final rule in order to address

the additional area of command and control for multi-unit events, including the need for the

acquisition of offsite assistance.

101

Equipment

The MBDBE rule contains requirements for licensee equipment that is relied upon for

use in mitigation strategies and guidelines. This final rule makes generically applicable

requirement (2) in attachments 2 and 3 of the Mitigation Strategies Order, which reads as

follows: “These strategies must… have adequate capacity to address challenges to core

cooling, containment, and SFP cooling capabilities at all units on a site subject to this Order.”

The industry guidance of NEI 12-06, as endorsed by NRC interim staff guidance

JLD-ISG-2012-01, included specifications for each licensee’s provision of a spare capability in

order to assure the reliability and availability of the equipment required to provide the capacity

and capability requirements of the Mitigation Strategies Order. (Section X, “Backfitting and

Issue Finality,” of this notice contains a discussion of the guidance supporting the MBDBE rule,

including its relation to the guidance developed to support implementation of the Mitigation

Strategies and SFPI orders.) This “spare capability” was also referred to within the guidance as

an “N+1” capability, where “N” is the number of power reactor units on a site. The NRC

considered including requirements similar to the spare capability specification of NEI 12-06 in

this rule but determined that such an inclusion would be too prescriptive and could result in the

need to grant exemptions for alternate approaches that provide an effective and efficient means

to provide the required capability. One example of this is in the area of flexible hoses, for which

a strict application of the spare capability guidance could necessitate a licensee’s provision of

spare hose or cable lengths sufficient to replace the longest run of hoses being used by the

licensee, when significant operating experience with similar hoses for fire protection does not

show a failure rate that would support the need for such a spare capability.

The development of the mitigation strategies in response to the Mitigation Strategies

Order relied upon a variety of initial and boundary conditions that were provided in the

102

regulatory guidance of JLD-ISG-2012-01 and NEI 12-06. These initial and boundary conditions

followed the philosophy of the basis for imposition of the requirements of the Mitigation

Strategies Order, which was to require additional defense-in-depth measures to provide

continued reasonable assurance of adequate protection of public health and safety. As a result,

the industry response to the Mitigation Strategies Order includes diverse and flexible means of

accomplishing safety functions rather than providing an additional further hardened train of

safety equipment. These requirements and conditions included the acknowledgement that, due

to the fact that initiation of an event requiring use of the strategies would include multiple failures

of safety-related SSCs, it is inappropriate to postulate further failures that are not consequential

to the initiating event. As a result, the NRC has determined that the conditions to which the

instrumentation (as a class of equipment), that would be relied on for the mitigation strategies,

would be exposed do not include conditions stemming from fuel damage, but instead. Instead

those conditions are limited to the initial and boundary conditions set forth in the guidance and

include the conditions assumed to result from a postulated beyond-design-basis external event

used in developing the guidelines and strategies under the MBDBE rule. The NRC has

determined that it should not be necessary for the instrumentation to be designed specifically for

use in the mitigation strategies and guidelines, but instead it would be necessary that the design

and associated functional performance be sufficient to meet the demands of those strategies

(i.e., a licensee may rely upon existing instrumentation that is capable of operating in the

conditions anticipated for the required strategies and guidelines rather than replacing it with new

instrumentation specifically designed for those conditions). For example, NEI 12-06, which is

endorsed in RG 1.226, includes a discussion in section 3.2.1.12 regarding the basis that should

be provided for plant equipment that is relied upon in the mitigation strategies.

103

The MBDBE requirements cover events that are not included in design-basis events as

that term is used in the § 50.2 definition of “safety-related structures, systems, and

components.” Because of this, reliance on equipment for use in the mitigation strategies does

not result in the applicability of the principal design criterion (PDC) as described in 10 CFR part

50, appendix A, “General Design Criteria for Nuclear Power Plants,” General Design Criterion

(GDC) 2, “Design bases for protection against natural phenomena,” or the principal design

criterion (PDC) applicable to a plant’s operating license if the license was issued prior to the

effective date of GDC 2..” The MBDBE rule requires reasonable protection for the equipment

relied on for the mitigation strategies against the effects of natural phenomena that are

equivalent in magnitude to the phenomena assumed for developing the design basis for the

facility under GDC 2 or the applicable PDC. In some cases, the reevaluated seismic and

flooding hazards determined in response to the March 12, 2012, NRC letter issued under §

50.54(f), as assessed by the NRC, may show that increased protection is necessary. The

licensees and the NRC are currently evaluating the effects of these reevaluated hazards during

the development of the MBDBE rule. However, completion of these efforts necessitates the use

of a flexible scheduling provision in the MBDBE rule as discussed elsewhere in this notice..

As discussed in COMSECY-14-0037 and its associated SRM, the requirements of the

Mitigation Strategies Order were imposed in parallel with the agency’s March 12, 2012, requests

for information on the reevaluation of external hazards. As a result, the Mitigation Strategies

Order included a requirement in both attachment 2 and 3 for licensees to provide reasonable

protection for equipment associated with the required mitigation strategies from external events

without specific reference to the necessary level of protection. The appropriate level of

protection from external hazards, particularly flooding, was the subject of discussion in the

course of NRC-held public meetings leading up to the issuance of JLD-ISG-2012-01 and its

104

endorsement of the industry guidance for the Mitigation Strategies Order, NEI 12-06.

Section 6.2.3.1 of NEI 12-06 specifies that the level of protection for flooding should be “the

flood elevation from the most recent site flood analysis. The evaluation to determine the

elevation for storage should be informed by flood analysis applicable to the site from early site

permits, combined license applications, and/or contiguous licensed sites.” The choice of this

hazard level was driven by the recognition that, while the flooding hazard reevaluations by

holders of operating licenses and construction permits may not be complete in advance of the

development and implementation of the mitigation strategies, information available from flood

analyses for nearby sites could be taken into account in choosing the appropriate hazard level

in order to avoid the need for rework or modification of the strategies. Many licensees took the

former approach, using their best estimates of potential hazard levels and providing additional

margin to the current licensing basis. (See, e.g., the description of the flooding strategies for

Fort Calhoun Station on page B-43 et seq., of Omaha Public Power District’s Overall Integrated

Plan in response to the Mitigation Strategies Order, referenced in section XIX of this notice.)

In COMSECY-14-0037, the NRC staff requested that the Commission affirm that:

1) licensees for operating nuclear power plants need to address the reevaluated flooding

hazards within their mitigation strategies for beyond-design-basis external events; 2) licensees

for operating nuclear power plants may need to address some specific flooding scenarios that

could significantly damage the power plant site by developing targeted or scenario-specific

mitigation strategies, possibly including unconventional measures, to prevent fuel damage in

reactor cores or SFPs; and 3) the NRC staff should revise the flooding assessments and

integrate the decision making into the development and implementation of mitigation strategies

under the Mitigation Strategies Order and this rulemaking. These principles reflect the NEI 12-

06 reference to the “most recent flood analysis” previously discussed and the documentation by

105

licensees in their overall integrated plans for the mitigation strategies that, at the time of their

submittals, “flood and seismic reevaluations pursuant to the § 50.54(f) letter of March 12, 2012,

are not completed and therefore not assumed in this submittal. As the reevaluations are

completed, appropriate issues would be entered into the corrective action system and

addressed on a schedule commensurate with other licensing bases changes.” In SRM-

COMSECY-14-0037, the Commission approved the first two items recommended by the NRC

staff, regarding the need for operating nuclear power plant licensees to address the reevaluated

flood hazards within the mitigation strategies and the potential for using targeted or scenario-

specific mitigation strategies. The Commission did not approve the third recommendation;

however, that recommendation would have been outside the scope of this rulemaking effort.

The MBDBE rule reflects this Commission direction by the inclusion of the requirements in

§ 50.155(b)(2).

Because the events for which the mitigation strategies are to be used are outside the

scope of the design -basis events considered in establishing the basis for the design of the

facility, equipment that is relied upon solely for those mitigation strategies does not fall within the

scope of § 50.65. (the Maintenance Rule). Nevertheless, the equipment used to implement the

mitigation strategies must receive adequate maintenance in order to assure that it is capable of

fulfilling its intended function, and thereby ensure that the requirement to develop, implement,

and maintain the mitigation strategies continues to be met.

This rulemaking does not revise the regulatory treatment of equipment relied upon for

the EDMGs now relocated to § 50.155(b)(32). The regulatory treatment of that equipment

remains as it is described in NEI 06-12, the endorsed guidance document for those strategies

and guidelines.

106

The NRC recognizes that existing nuclear power reactors with operating licenses issued

under 10 CFR part 50 and those new nuclear power reactors with COLs issued under

10 CFR part 52 or operating licenses issued under 10 CFR part 50 may establish different

approaches in developing strategies to mitigate beyond-design-basis events. For example, new

nuclear power plants may use installed plant equipment for both the initial and long-term

response to a loss of all ac power with less reliance on offsite resources than existing nuclear

power reactors. Under § 50.155(c), the NRC will consider the specific plant approach when

evaluating the SSCs relied on as part of the mitigation strategies for beyond-design-basis

events.

107

Training

The mitigation of the effects of beyond-design-basis events using the strategies and

guidelines is principally accomplished through manual actions rather than automated plant

responses. Additionally, the instructions provided for event mitigation may be largely provided

as high level strategies and guidelines rather than step-by-step procedures. The use of

strategies and guidelines supports the ability to adapt the mitigation measures to the specific

plant damage and operational conditions presented by the event. However, effective use of this

flexibility depends upon the knowledge and abilities of personnel to select appropriate strategies

or guidelines from a range of options and implement mitigation measures using equipment or

methods that may differ from those employed for normal operation or design-basis event

response. As a result, the NRC considers personnel training and qualification necessary to

ensure that individuals are capable of effectively performing the roles and responsibilities

established in the strategies and guidelines that are required by this rule.

The NRC acknowledges that licensee training programs, such as those required for

licensed operators under 10 CFR part 55, “Operators’ Licenses,” the programs for plant

personnel specified under § 50.120, “Training and qualification of nuclear power plant

personnel,” and the training for emergency response personnel required by 10 CFR part 50,

appendix E, section IV.F, “Training,” likely provide for the knowledge and abilities required for

performing activities described in the strategies and guidelines that are required by this rule.

Nevertheless, as noted previously, the strategies and guidelines may use new methods or

equipment that require knowledge and abilities not currently addressed under existing training

programs and, as a result, there may be gaps in these training programs that must be

addressed to support effective use of the strategies and guidelines. Accordingly, the MBDBE

rule further requires that licensees provide for the training of personnel using the SAT process

108

as defined in § 55.4, except for elements already covered under other NRC regulations. The

SAT process, which is acceptable for meeting training requirements under 10 CFR part 55 and

§ 50.120, also is appropriate for licensee identification and resolution of any current gaps or

future modifications to personnel training that may be necessary to provide for the training of

personnel performing activities described in the mitigation strategies and guidelines that are

required by this final rule. The NRC recognizes that there are other training programs that are

currently acceptable for meeting other regulatory required training (e.g., 10 CFR part 50,

appendix E, section IV.F) that do not use the SAT process. In light of the existence of these

training programs, which have been found acceptable for more frequently occurring design-

basis events, the NRC has determined that these training programs can meet the needs for

common elements with beyond-design-basis event mitigation. Therefore, the NRC is not

requiring licensees to revise these training programs to use the SAT process to meet the

MBDBE rule requirements. Licensees are required to use the SAT process for newly identified

training requirements supporting the effective use of the strategies and guidelines that are

required by this rule.

By using the SAT process, licensees identify and train on any additional tasks that are

necessary to implement the strategies and guidelines for the mitigation of beyond-design-basis

events as defined in this final rule. The additional tasks identified are incorporated into the

training program to ensure appropriate training is administered for each qualified individual

designated to implement the strategies and guidelines required by this rule.

Drills or Exercises

As described in the discussion of training requirements, the NRC is requiring licensees

to conduct drills or exercises to provide assurance that licensee staff are properly trained and

can demonstrate implementation of the mitigation strategies and guidelines. The drill or

109

exercise requirement satisfies the SAT element for evaluation and revision of the training based

on the performance of trained personnel in the job setting found in § 55.4.

In addition, the drill requirement for strategies and guidelines under § 50.155(b)(3)

results from moving § 50.54(hh)(2) to the new § 50.155(b)(3) and the movement of the

accompanying training requirement from 10 CFR part 50, appendix E, section F.2.j.

Licensees are required to demonstrate a capability to use at least one of the strategies

and guidelines developed to comply with paragraph 50.155(b)(1) or (b)(2) and paragraph

50.155(b)(3). The requirement related to § 50.155(b)(2) applies to holders of operating licenses

under 10 CFR part 50 as of the effective date of the rule, for whom the provisions related to

reevaluated hazards apply. Licensees for all combined licenses issued under 10 CFR part 52

and those operating licenses issued after the effective date of the rule would have considered

information similar to the reevaluated hazard provisions in the establishment of their design

bases. The selection of strategies and guidelines for demonstration, where there is an option,

would depend on licensee consideration of various factors, including how these strategies and

guidelines are already used. Licensees that comply with § 50.155(b)(2) by developing event-

specific approaches that rely on normal operating procedures or AOPs such as severe weather

preparation procedures that are used routinely, would generally not treat these approaches as

strategies and guidelines for the purposes of the drill requirements and would use the strategies

and guidelines developed to comply with § 50.155(b)(1) instead in their drills or exercises.

Conversely, licensees that comply with § 50.155(b)(2) by developing targeted or scenario-

specific mitigation strategies, possibly including unconventional measures, would be expected

to demonstrate these event-specific approaches under the drill requirements.

Spent Fuel Pool Monitoring

110

The MBDBE rule requires licensees to have a means to remotely monitor wide-range

SFP level as a separate requirement within the MBDBE rule, which makes the requirements of

the SFPI Order generically applicable. While many licensees make use of this instrumentation

to support implementation of the mitigation strategies, the instrumentation requirement was

imposed under the SFPI Order to address the potential for the licensee personnel to be

distracted from other issues by the status of the SFP, and thereby enable the operators to

re-prioritize resources, if necessary, following a beyond-design-basis external event. This

requirement has a separate purpose from the mitigation strategies requirements: to provide a

reliable indication of the water level in the SFP to allow prioritization of response actions

between the core and the SFP. Therefore, this requirement was moved to paragraph (fe) in the

final rule to ensure a continued separation of the requirements. The NRC considered including

the detailed requirements from the SFPI Order within the MBDBE rule, but determined that the

more performance-based approach taken with this rule allows an applicant for a new reactor

license or design certification to provide innovative solutions to address the need to effectively

prioritize event mitigation and recovery actions between the source term contained in the

reactor vessel and that contained within the SFP.

In the course of implementation of the SFPI Order requirements, one lesson learned was

that the need for prioritization of event mitigation and recovery actions is inapplicable to SFPs

for which the decay heat load is sufficiently low that SFP cooling is not challenged in the same

time frame as event progression for the reactor core. This was documented in the regulatory

guidance of JLD-ISG-2012-03 and NEI 12-02, “Industry Guidance for Compliance with NRC

Order EA-12-051, ‘To Modify License with Regard to Reliable Spent Fuel Pool

Instrumentation’,”Instrumentation,’” Revision 1, which eliminates from the definition of an

applicable SFP a pool that does not contain fuel used for the generation of power within the

111

preceding 5 years. This is clarified in the MBDBE rule in § 50.155(fe) by including a termination

of the requirement once 5 years have elapsed since the fuel within the pool was last used for

power generation in a reactor vessel.

Documentation of Changes

Because the MBDBE rule requirements address beyond-design-basis events, currently

existing change control processes, including most notably § 50.59, may not address all aspects

of a contemplated change to the strategies and guidelines under this rule. Therefore, the

MBDBE rule includes a provision intended to supplement the existing change control processes

and focus on the beyond-design-basis aspects of proposed changes. The MBDBE rule does not

contain criteria typically included in other change control processes that are used as a threshold

for determining when a licensee needs to seek NRC review and approval prior to implementing

the proposed change. Instead, the MBDBE rule requires that licensees perform evaluations of

proposed changes sufficient to reach a conclusion that the MBDBE rule requirements continue

to be met, and to document and maintain this evaluation to support NRC oversight of these

activities. The final rule is revised to more clearly reflect this approach by referring to these

requirements in § 50.155(gf) as “Documentation of Changes.”

The NRC requested stakeholder feedback concerning the change control provisions for

the MBDBE rule. The feedback provided is discussed in sectionSection IV of this

noticedocument. The NRC concludes that the final rule will follow the same approach contained

in the proposed rule as discussed in sectionSection VI of this noticedocument. Notwithstanding

this conclusion, the NRC is revising the discussion in this noticedocument for this provision to

clarify its meaning and intent.

112

The NRC determined that the changes whose acceptability would be most difficult to

judge are those that do not fall within endorsed guidance or are not NRC-approved alternative

approaches taken at another licensed facility that can be demonstrated to apply to the

licensee’s facility. Changes to the implementation of the MBDBE requirements that remain

consistent with regulatory guidance are clearly acceptable, because such changes ensure

continued compliance with the MBDBE requirements. The NRC recognizes that licensees may

wish to make changes to the implementation of these requirements that do not follow current

regulatory guidance for this rulemaking, and that are not an approved alternative that the

licensee can demonstrate applies to their facility. To clarify the MBDBE rule requirements for

documentation of changes, the NRC added additional information to sectionSection VI of this

noticedocument that discusses potential changes, which are outside endorsed guidance or

approved alternatives, that would clearly not constitute “demonstrated compliance.”

During public discussions before issuance of the proposed rule, a stakeholder suggested

that the NRC should consider a provision to allow a licensee to request NRC review of a

proposed change, and that if the NRC did not act upon the request for a suggested time period

(e.g., 180 days), then the request would be considered “acceptable,” similar to the process for

changes to the quality assurance program description under § 50.54(a)(4)(iv). The NRC did not

include this form of tacit approval process in the MBDBE rule and instead included provisions in

the MBDBE rule to place on licensees the responsibility for ensuring that proposed changes

result in continued compliance with the rule, subject to NRC oversight, or are otherwise

submitted to the NRC under the § 50.12 exemption process.

A licensee may intend to change its facility, procedures, or guideline sets to revise some

aspect of beyond-design-basis mitigation governed by the MBDBE rule in a manner that can

impact multiple aspects of the facility, including “design basis” aspects of the facility subject to

113

other regulations and change control processes. As previously discussed, the NRC anticipates

that licensees will ensure that changes to the implementation of the MBDBE requirements are

consistent with endorsed guidance, or otherwise demonstrate continued compliance with the

MBDBE rule. This same change also could impact safety-related SSCs, either directly (e.g., a

proposed change that impacts a physical connection of mitigation strategies equipment to a

safety-related component or system) or indirectly (e.g., a proposed change that involves the

physical location of mitigation equipment in the vicinity of safety-related equipment that presents

a potential for adverse physical/spatial interactions with safety-related components). As a

result, § 50.59 and other change control processes, as appropriate, would need to be applied to

evaluate the proposed change for acceptability under any other applicable change control

process.

Additionally, proposed changes can impact numerous aspects of the facility beyond the

safety-related impacts, including implementation of fire protection requirements, security

requirements, emergency preparedness requirements, or safety/security interface requirements.

A licensee must therefore ensure that all applicable change control provisions are used to judge

the acceptability of facility changes including, for example, change control requirements for fire

protection, security, and emergency preparedness.. Additionally, recognizing the nature of

mitigation strategies and the reliance on human actions, a licensee also needs to ensure that

the proposed changes satisfy the safety/security interface requirements of § 73.58. While the

obligation of a licensee to comply with all applicable requirements might be viewed as making

the provision in § 50.155(gf)(2) unnecessary, the NRC recognizes the potential complexity of

proposed facility changes and the complexity of existing regulatory requirements that govern

change control. Therefore, the NRC concluded that adding the § 50.155(gf)(2) provision for

documentation of changes was warranted for the purposes of regulatory clarity.

114

Implementation

Paragraph 50.155(h)(1g) provides a 2-year implementation period to provide sufficient

time to implement portions of the MBDBE rule that were not completed as part of the Mitigation

Strategies and SFPI Orders, address the reevaluated hazards information required by

§ 50.155(b)(2), and allow licensees to review their previous compliance with the Mitigation

Strategies and SFPI Orders and make any necessary changes to programs, plans, procedures,

and guidelines to reflect and reference the newly issued § 50.155 requirements. This

implementation period is 3 years for licensees that received Order EA-13-109. These licensees

are allowed an additional year of implementation in order to alleviate CER by allowing the same

amount of time following achievement of full compliance with that order, which was issued a

year after the Mitigation Strategies and SFPI Orders.

As discussed in section IV of this notice, the NRC received feedback indicating that

power reactor licensees cannot complete implementation of the requirements of the MBDBE

rule within 2 years of the effective date of the rule. The feedback focused on the

implementation of the requirements for licensees to address the effects of reevaluated hazards

contained in § 50.155(b)(2). The NRC agrees with the need for providing schedule flexibility,

and concludes that providing the flexibility is acceptable given licensees’ prior implementation of

the remaining requirements in the MBDBE rule under the scheduling requirements of the

Mitigation Strategies and SFPI Orders, which significantly enhances licensees’ capabilities to

mitigate beyond-design-basis events. The NRC took into consideration the potential benefit of

allowing licensees to understand the potential impact of addressing the reevaluated hazard

information prior to implementing plant changes. By evaluating this impact first, licensees may

avoid unnecessary costs incurred in changing planned modifications. As part of the schedule

115

submittal, licensees will discuss the basis for the extended schedule, including why the licensee

concludes that safety is maintained for the implementation time period. The flexible scheduling

provision of § 50.155(h)(3) provides the NRC with the opportunity to notify the licensee of the

unacceptability of a proposed schedule that is not appropriately justified in the event that it

poses undue risk to public health and safety. Paragraph 50.155(h)(3) also reduces the

regulatory burden on the licensee and the NRC by allowing for tacit approval of the schedule

after a reasonable period of time available for consideration.

In contrast with the portions of the final MBDBE rule that make the Mitigation Strategies

and SFPI Orders generically applicable, § 50.155(b)(32) continues the requirements that were

previously in § 50.54(hh)(2). Currently operating power reactor licensees have all achieved

compliance with these requirements. Therefore, § 50.155(h)(1g) requires that licensees subject

to the requirements of § 50.155(b)(32) continue to comply with those requirements during the

implementation period for the remainder of the final MBDBE rule.

Onsite and offsite communications capability

The MBDBE rule requires communication capabilities for events that result in loss of all

ac power onsite, or potential destruction of offsite communications infrastructure. Because of

the destruction to communications capability that occurred during the Fukushima Dai-ichi event,

the MBDBE rule contains requirements for licensees to provide a capability to communicate with

onsite staff to support mitigation of the event, and to support offsite communications to gain any

additional support or to perform emergency preparedness functions. The communication

requirements support effective implementation of the mitigation strategies and guidelines of

§ 50.155(b)(1) and were included as part of the implementation of the Mitigation Strategies

Order. These requirements are relocated in the final MBDBE rule, as previously discussed in

116

section IV of this notice, to more clearly reflect the importance of communication to effective

implementation of the mitigation strategies and guidelines, and to better align with the previous

implementation of these requirements under the Mitigation Strategies Order.

In its letter issued on March 12, 2012, pursuant to § 50.54(f), the NRC requested

information associated with NTTF recommendation 9.3 for emergency preparedness

communications. Specifically, the letter requested licensees submit an assessment of their

current communications systems and equipment used during a beyond-design-basis natural

event resulting in an ELAP to all units on site and impeding access to the site. The § 50.54(f)

letter cites § 50.47(b)(6) and 10 CFR part 50, appendix E, section IV.E.9 as the applicable

regulations that describe the licensee’s emergency plan communications systems

requirements. The communications systems used by licensees to meet these regulations are

the communications systems that were to be considered in the requested assessment. The

intent of the communications assessment was to determine what, if any, enhancements would

be needed for onsite communications systems (e.g., radios for response teams and between

facilities) and offsite communications systems (e.g., cellular telephones and satellite telephones)

used in support of required mitigative response actions during a site-wide loss of all ac power to

ensure continued availability.

Therefore, any communication capability enhancement made by a licensee in response

to the assessment did not need to meet the design capabilities for the communications system

required by 10 CFR part 50, appendix E or testing frequencies described for primary and

backup onsite and offsite communications systems. Any enhanced communications system,

equipment, or power supply implemented as a result of the § 50.54(f) assessment was not

necessary to meet the requirement to notify offsite emergency response organizations within 15

minutes of an emergency declaration or to meet the monthly communications testing

117

requirement for contiguous State/local governments within the plume exposure pathway

emergency planning zone.

Order Rescission and Removal of License Conditions

Order Withdrawal and Removal of License Conditions

The NRC is including in the final rule specific terms that rescindwithdraw orders and

remove license conditions that are substantively redundant with provisions in the final rule. As

discussed in this section, a primary objective of this rulemaking is to make the requirements of

the Mitigation Strategies and SFPI Orders generically applicable to power reactor licensees and

applicants, taking into account lessons learned in the orders’ implementation and stakeholder

feedback received through the regulatory process. As such, the requirements of § 50.155 fully

replace the requirements of those orders. Although the orders provide for their relaxation or

rescission on a licensee-specific basis, use of that process would be an inefficient and

unnecessary administrative burden on licensees and the NRC—with no impact on public health

and safety—because the final rule simultaneously replaces the orders in their entirety for all

applicable licensees. Therefore, the NRC finds that good cause is shown to rescindwithdraw

the Mitigation Strategies and SFPI Orders for all licensees that received those orders once the

MBDBE rule goes into effect and licensees are in compliance with it. The rescissionwithdrawal

date for these orders was set to be the latest date for compliance by licensees in receipt of the

orders to prevent a regulatory gap; licensees proposing an alternative compliance schedule

would need to address achievement of compliance with the requirements of the MBDBE rule

corresponding to these orders prior to the rescission date in the rule in order to show good

cause for the alternate compliance schedule.

118

Order EA-06-137 concerns mitigation strategies for large fires or explosions at nuclear

power plants. This order was issued to certain licensees who received Order EA-02-026, which

required licensees to take specific interim compensatory measures, including mitigation

strategies for large fires or explosions at nuclear power plants, in light of the then-high-level

threat environment. Order EA-06-137 required that licensees receiving the order incorporate

into their security plans certain key mitigation strategies for large fires or explosions. The

requirement that these strategies be incorporated in security plans was subsequently relaxed by

letter dated August 28, 2006, which permitted licensees to consent to having their licenses

amended to incorporate a license condition on the subject. Several licensees had these license

conditions imposed by administrative license amendment (e.g., “Browns Ferry Nuclear Plant,

Units 1, 2, and 3 – Conforming License Amendments To Incorporate the Mitigation Strategies

Required by Section B.5.b. of Commission Order EA-02-026 and the Radiological Protection

Mitigation Strategies Required by Commission Order EA-06-137,” dated August 16, 2007). In

its Power Reactor Security Requirements final rule, the NRC established in § 50.54(hh)(2) a

regulation that provides a performance-based requirement that encompasses the mitigation

strategies required under Order EA-06-137 and its associated license condition. The MBDBE

rule moves § 50.54(hh)(2) to the new § 50.155(b)(3). As a result, neither Order EA-06-0137 nor

the license condition is necessary once the MBDBE rule goes into effect. Accordingly, the NRC

finds that good cause is shown to rescind Order EA-06-137 for each licensee that received the

order. Because the new § 50.155(b)(3) provides the same requirements as the license

condition associated with Order EA-06-0137, the license condition is deemed removed from

each applicable power reactor license once the MBDBE rule goes into effect.

Order EA-02-026 included a section, numbered B.5.b, in its attachment 2, requiring

mitigation strategies for large fires or explosions at nuclear power plants. Extensive interactions

119

among the NRC, industry, and licensees refined the strategies required by the order. In 2007,

the NRC issued to all then-operating power reactor licensees an administrative license

amendment (e.g., “Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 - Conforming License

Amendments to Incorporate the Mitigation Strategies Required by Section B.5.b. of Commission

Order EA-02-026,” dated July 11, 2007), containing a license condition entitled, “Mitigation

Strategy License Condition,” which required licensees to use 14 mitigation strategies. In the

Power Reactor Security Requirements final rule, the NRC established in §§ 50.54(hh), 50.34(i),

and 52.80(d) regulations that made the requirements of Order EA-02-026 generically applicable

to power reactor licensees and applicants. In the Power Reactor Security Requirements final

rule, the Commission explained that operating power reactor licensees already had procedures

in place that complied with the new § 50.54(hh)(2). Licensees used the same implementation

guidance to comply with the Mitigation Strategy License Condition as they used to comply with

§ 50.54(hh)(2); consequently, compliance with § 50.54(hh)(2) is sufficient to comply with the

Mitigation Strategy License Condition. Subsequently, the NRC rescinded Order EA-02-026,

section B.5.b by letter dated November 28, 2011, based on the fact that the regulations

encompassed the order requirements. Because licensees comply with both the regulations and

Mitigation Strategy License Condition via the same guidance, such that the former

§ 50.54(hh)(2) requirements encompass the license condition requirements, the NRC concludes

that § 50.155(b)(3) fully replaces the requirements that exist in the Mitigation Strategy License

Condition. Accordingly, under new § 50.155(i), the Mitigation Strategy License Conditions

imposed in 2007 are deemed removed from the licenses for those licensees that received that

license condition.

The NRC is also removing certain license conditions contained within the COLs held by

Detroit Edison Company (for Enrico Fermi Nuclear Plant, Unit 3), South Carolina Electric & Gas

120

Company (for Virgil C. Summer Nuclear Station, Units 2 and 3), Duke Energy Carolinas, LLC

(for William States Lee III Nuclear Station, Units 1 and 2), Dominion Virginia Power (for North

Anna Power Station, Unit 3),) and Florida Power &and Light Company (for Turkey Point, Units 6

and 7). These licensees did not receive the Mitigation Strategies and SFPI Orders because the

NRC had not issued COLs to these licensees at the time the NRC issued the Orders. When the

NRC issued those COLs, it included license conditions that are equivalent to the orders’

requirements. Because the license conditions contain the same requirements as the orders,

and the provisions of § 50.155 replace the requirements imposed by the orders, the license

conditions contain requirements equivalent to § 50.155 and will not be necessary once the

MBDBE rule goes into effect. Therefore, the mitigation strategies for beyond-design-basis

external events license conditions will be deemed removed from the Enrico Fermi Nuclear Plant,

Unit 3, Virgil C. Summer Nuclear Station, Units 2 and 3, William States Lee III Nuclear Station,

Units 1 and 2, North Anna Power Station, Unit 3, and Turkey Point, Units 6 and 7 COLs on

[INSERT THE EFFECTIVE DATE OF THE FINAL RULE30 DAYS AFTER PUBLICATION].

In addition to license conditions corresponding to the Mitigation Strategies Orders, the

COLs for Enrico Fermi Nuclear Plant, Unit 3, William States Lee III Nuclear Station, Units 1 and

2, North Anna Power Station, Unit 3, and Turkey Point, Units 6 and 7 included license

conditions for the performance of staffing and communications assessments that correspond to

the requests for information on those subjects in the NRC letter issued under § 50.54(f) on

March 12, 2012. As discussed in the backfit assessment for § 50.155(b)(5) and (c)(4), the NRC

used the information gathered in response to this letter in assessing the need to impose those

additional requirements on the licensees on a generic rather than site-specific

basis. ConsequentlyAs discussed in COMSECY-13-0010, “Schedule and Plans for Tier 2 Order

on Emergency Preparedness for Japan Lessons Learned,” with regard to the interaction

121

between licensee response to the § 50.54(f) letter and compliance with the Mitigation Strategies

Order, “the implementation of NEI 12-06 has a dependency on NEI 12-01, ‘Guideline for

Assessing Beyond Design Basis Accident Response Staffing and Communications Capabilities,’

which was developed to address Tier 1 NTTF 9.3 Recommendation regarding staffing and

communications. NEI 12-06 will utilize the staffing and communication resources identified in

NEI 12-01.” Because the implementation of the final rule uses the same guidance as an

acceptable means of compliance, there is no longer a need to collect this information for these

licensees because there will be no additional regulatory action taken to modify, suspend, or

revoke their licenses and the licensees are obligated to instead comply with the new

requirements. Therefore, the license conditions calling for staffing and communications

assessments for these licensees will be deemed removed on [INSERT THE EFFECTIVE DATE

OF THE FINAL RULE30 DAYS AFTER PUBLICATION].

Because the final rule removes certain license conditions without actually amending the

associated licenses, the NRC will issue by letter an administrative license amendment to each

applicable licensee that will remove the relevant license condition(s) from that licensee’s license

and include revised license pages.

For each of these orders being rescindedwithdrawn and license conditions being

removed, the NRC is replacing it with equivalent requirements in the MBDBE rule. Although the

NRC did not include these measures in the MBDBE proposed rule, the NRC has good cause for

not providingprovided sufficient notice and an opportunity to comment on them. Underunder the

Administrative Procedure Act (5 U.S.C. 553(b)), an agency may waive)) when it issued the

normal notice and comment requirements if it finds, for good cause, that they are impracticable,

unnecessary, or contrary to the public interest. As authorized by 5 U.S.C. 553(b)(3)(B), the

NRC finds good cause to waive notice and opportunity for comment on the measures because

122

the measures will not change the applicable licensees’ substantive requirements or have an

impact on public health and safety or the common defense and security. The NRC is simply

replacing the method that it uses to impose the same requirements on the same set of

licensees. Removing the license conditions and rescinding the orders is also a logical

outgrowth of theMBDBE proposed rule, in which. In the proposed rule, the Commission

explained that the agencyNRC would make generically applicable certain requirements in the

Mitigation Strategies and SFPI Orders and related license conditions. The Commission’s

decision to rescind the orders and remove thethese license conditions now that they are

unnecessary was reasonably foreseeable. Similarly, Order EA-06-137 and its associated, just

as it was foreseeable that the Commission would withdraw the Orders. Additionally, the

Commission was informed by comments from the public that warned of potential unintended

consequences from having duplicate requirements in orders, license condition have not been

necessary since the 2009 Power Reactor Security Requirementsconditions, and regulations.

Thus, this aspect of the final rule created § 50.54(hh)., like the rest of the final rule, is a logical

outgrowth of the proposed rule. Under the logical outgrowth line of legal decisions (e.g., Long

Island Care at Home, Ltd. v. Coke, 551 U.S. 158 (2007); National Mining Ass’n v. Mine Safety

and Health Administration, 512 F.3d 696 (D.C. Cir. 2008)), the public had adequate notice and

opportunity to comment on the withdrawal of orders and removal of license conditions.

Technology-Neutral Emergency Response Data System

The requirements of 10 CFR part 50, appendix E, section VI, for the ERDS are amended

to reflect the use of up-to-date technologies and remain technology-neutral so that the

equipment supplied by the NRC continues to be replaced as needed, without the need for future

rulemaking as equipment becomes obsolete. In 2005, the NRC initiated a comprehensive,

123

multi-year effort to modernize all aspects of the ERDS, including the hardware and software that

constitute the ERDS infrastructure at NRC headquarters, as well as the technology used to

transmit data from licensed power reactor facilities. As described in NRC Regulatory Issue

Summary 2009-13, “Emergency Response Data System Upgrade from Modem to Virtual

Private Network Appliance,” the NRC engaged licensees in a program that replaced the existing

modems used to transmit ERDS data with virtual private network devices. The licensees now

have less burdensome testing requirements, faster data transmission rates, and increased

system security.

VI. Section-by-Section Analysis

§ 50.8 Information Collection Requirements: OMB Approval.

This section, which lists all information collections in 10 CFR part 50 that have been

approved by the Office of Management and Budget (OMB), is revised by adding a reference to

§ 50.155, the MBDBE rule. As discussed in sectionSection XIV, “Paperwork Reduction Act

Statement,” of this noticedocument, the OMB has approved the information collection and

reporting requirements in the MBDBE rule. No specific requirement or prohibition is imposed on

applicants or licensees in this section.

§ 50.34 Contents of Applications; Technical Information.

Section 50.34 identifies the technical information that must be provided in applications

for construction permits and operating licenses. Paragraphs (a) and (b) of this section identify

the information to be submitted as part of the preliminary or final safety analysis report,

respectively. Revised paragraph (i) of this section identifies information to be submitted as part

124

of an operating license application, but not necessarily included in the final safety analysis

report.

The NRC is making an administrative change to § 50.34(a)(13) and (b)(12) to remove

the word “stationary” from the requirement for power reactor applicants who apply for a

construction permit or operating license, respectively. Section 50.34(a)(13) and 50.34(b)(12)

were added to the regulations in 2009 to reflect the requirements of § 50.150(b) regarding the

inclusion of information within the preliminary or final safety analysis reports for applicants

subject to § 50.150. Section 50.34(a)(13) and (b)(12) were inadvertently limited to “stationary

power reactors,” matching the wording of § 50.34(a)(1), (a)(12), (b)(10), and (b)(11), which

pertain to seismic risk hazards for stationary power reactors. The NRC is not changing the

meaning of this requirement by removing the word “stationary” from these requirements. This

change is to ensure consistency in describing the types of applications to which the

requirements apply.

Section 50.34(i) requires each application for an operating license to include the

applicant’s plans for implementing the requirements of § 50.155 including a schedule for

achieving full compliance with these requirements. This paragraph also requires the application

to include a description of: 1) the integrated response capability required by § 50.155(b) and 2)

the equipment upon which the strategies and guidelines required by § 50.155(b)(1) rely,

including the planned locations of the equipment and how the equipment and SSCs would meet

the design requirements of § 50.155(c).

§ 50.54 Conditions of Licenses.

This rulemaking designates § 50.54(hh)(3) as § 50.54(hh)(2) to reflect the movement of

the requirements formerly in § 50.54(hh)(2) to § 50.155(b)(32). Section 50.54(hh)(2) is revised

125

to reflect that § 50.54(hh)(1)’s applicability is applies to the licensee rather than the facility and

to correct the section numbers for the required certifications. Additionally, To avoid an

unnecessary backfit in § 50.54(hh)(2) clarifies that), in the inapplicability is dependent uponfinal

rule the NRC docketing ofremoves the words “once the NRC has docketed those certifications

rather than licensee submittal because” from the proposed § 50.82(a54(hh)(2) and § 52.110(b)

set docketing as the point at which operation of the reactor is no longer authorized and fuel

cannot be placed in the reactor vessel.).

§ 50.155 Mitigation of Beyond-Design-Basis Events.

This final rule adds new § 50.155 Mitigation of beyond-design-basis events to

10 CFR part 50. The details of each paragraph within § 50.155 isare explained in greater detail

in the following paragraphs in this section.

Paragraph 50.155(a), “Applicability”

Paragraph 50.155(a) describes which entities are subject to the MBDBE rule.

Paragraph 50.155(a)(1) provides that each holder of an operating license for a nuclear power

reactor under 10 CFR part 50, as well as each holder of a COL under 10 CFR part 52 for which

the Commission has made the finding under § 52.103(g) that the acceptance criteria have been

met, is required to comply with the requirements of this rule until the time when the NRC has

docketed the certifications described in § 50.82(a)(1) or § 52.110(a). These certifications inform

the NRC that the licensee has permanently ceased to operate the reactor and permanently

removed all fuel from the reactor vessel. Upon the docketing of the certifications, by operation

of law under §§ 50.82(a)(2) or 52.110(b), the licensee’s 10 CFR part 50 or 52 license,

respectively, no longer authorizes operation of the reactor or emplacement or retentionThe

126

permanent removal of fuel intofrom the reactor vessel. removes the possibility of core damage

and containment failure, making it appropriate to terminate the requirements for strategies and

guidelines to maintain or restore core cooling and containment capabilities. At the time of NRC

docketing ofthe licensee submits these certifications, control of the applicability of the

requirements of § 50.155 for licensees transitions to § 50.155(a)(2).

Although an applicant for an operating license under 10 CFR part 50 or a COL holder

before the § 52.103(g) finding is not required to comply with § 50.155 until issuance of the

operating license or the making of the § 52.103(g) finding, respectively, these entities must

include in their applications information under paragraph§ 50.34(i) or paragraph§ 52.80(d),

respectively, including a schedule for achieving full compliance with the requirements of

§ 50.155. This information includes the schedule for performance of the drill or exercise under

§ 50.155(e)(1) or (2). The treatment of this initial drill or exercise is comparable to the NRC’s

treatment of the initial emergency preparedness exercise in 10 CFR part 50, appendix E,

section F.2.a. prior to the issuance of the operating license or making of the § 52.103(g) finding.

Paragraph 50.155(a)(2) addresses power reactor licensees that permanently stop

operating and defuel their reactors and begin decommissioning the reactors. Paragraph

50.155(a)(2)(i) provides that when an entity subject to the requirements of § 50.155 submits to

the NRC the certifications described in §§§ 50.82(a)(1) or § 52.110(a), and the NRC dockets

those certifications, then that licensee is required to comply only with the requirements of

§ 50.155(b) through (ed), and (gf) associated with maintaining or restoring SFP cooling

capabilities for the reactor described in the § 50.82(a)(1) or § 52.110(a) certifications. In other

words, the licensee may discontinue compliance with the requirements in § 50.155 associated

with maintaining or restoring core cooling or the primary reactor containment functional

capability for the reactor described in the § 50.82(a)(1) or § 52.110(a) certifications.

127

Compliance with the requirements of § 50.155(b) through (ed), and (gf) associated with

maintaining or restoring SFP cooling capabilities continues as long as spent fuel remains in the

SFPs associated with the reactor described in the § 50.82(a)(1) or § 52.110(a) certifications, or

until the criterion of § 50.155(a)(2)(ii) can be satisfied. Once those conditions are satisfied,

control of the applicability of the requirements of § 50.155 for licensees transitions to

paragraphs 50.155(a)(2)(iv) or 50.155(a)(2)(ii), respectively.

Paragraph 50.155(a)(2)(ii) discontinues all the requirements of § 50.155 except those

provided in § 50.155(b)(32) once the decay heat of the fuel in the SFP can be removed solely

by heating and boiling of water within the SFP and the boil-off period provides sufficient time for

the licensee to obtain off-site resources to sustain the SFP cooling function indefinitely. To

comply with the requirement of § 50.155(a)(2)(ii), licensees must perform and retain an analysis

demonstrating that sufficient time has passed since the fuel within the SFP was last irradiated

such that the fuel’s low decay heat and boil-off period provide sufficient time in an emergency

for the licensee to obtain off-site resources to sustain the SFP cooling function indefinitely.

Paragraph 50.155(a)(2)(iii) exempts the licensee for Millstone Power Station, Unit 1,

Dominion Nuclear Connecticut, Inc. from the requirements of § 50.155.

Paragraph 50.155(a)(2)(iv) allows holders of operating licenses or COLs for which the

NRC has docketed the certifications described in § 50.82(a)(1) or § 52.110(a) have been

submitted to cease compliance with all requirements in § 50.155, once a power reactor licensee

has permanently stopped operating, defueled its reactor, and removed all irradiated fuel from

the SFP(s) associated with the reactor described in the § 50.82(a)(1) or § 52.110(a)

certifications.

128

Paragraph 50.155(b), “Integrated response capability”)

Paragraph 50.155(b) requires that each applicant or licensee develop, implement, and

maintain an integrated response capability that includes: 1) mitigation strategies for beyond-

design-basis external events, 2) reevaluated seismic and flooding hazards mitigation strategies

and guidelines, or event-specific approaches, if applicable, 3) EDMGs, 4) integration of these

strategies and guidelines with EOPs, 5) sufficient staffing to support implementation of the

guidelines in conjunction with the EOPs, and 6) a supporting organizational structure with

defined roles, responsibilities, and authorities for directing and performing these strategies,

guidelines, and procedures.. The intent of this requirement is that the operating license and

COL holders described in § 50.155(a) be able to mitigate the consequences of a wide range of

initiating beyond-design-basis events and plant damage states that can challenge public health

and safety.

The specification of strategies, guidelines, and procedures for the response capability

not only defines the required scope of the capability but also sets forth the expectation that the

response capability must include planned methods for responding that are documented in some

form of written instruction. To serve their function, these strategies, guidelines, and procedures

must be used by trained licensee personnel capable of properly directing and implementing the

strategies and guidelines. Accordingly, § 50.155(b)(5), in conjunction with § 50.155(d), requires

that the response capability include an adequate number of licensee personnel with the

knowledge and skills to implement the strategies, guidelines, and procedures and that the

mitigation activities of these individuals be coordinated through a defined command and control

structure required by § 50.155(b)(6).

Paragraph 50.155(b) specifies that the integrated response capabilitymitigation

strategies for beyond-design-basis external events and EDMGs be “developed, implemented,

129

and maintained.” This language reflects NRC consideration that whereas certain elements of

the integrated response capability have been developed and are currently in place (e.g., the

EDMGs), other elements (e.g., guidelines to mitigate beyond-design-basis external events) may

require additional efforts to complete and integrate. The term “implement” is used in §

50.155(b) to mean that the integrated response capability ismitigation strategies for beyond-

design-basis external events and EDMGs are established and available to respond, if needed

(e.g., the licensee has approved the strategies, guidelines, and procedures for use). The term

“maintain” as used in § 50.155(b) reflects the NRC’s intent that licensees ensure that the

integrated response capabilitymitigation strategies for beyond-design-basis external events and

EDMGs, once established, be preserved, including the need to maintain equipment relied on for

the mitigation strategies such that the equipment is capable of fulfilling its intended function, and

consistent with the provisions for documentation of changes in § 50.155(gf).

Paragraph 50.155(b)(1) requires applicants and licensees to develop, implement and

maintain strategies and guidelines to mitigate beyond-design-basis external events from natural

phenomenonphenomena. These strategies and guidelines are developed assuming a loss of all

ac power concurrent with either an LUHS or, for passive reactor designs, a loss of normal

access to the normal heat sink. These provisions require that the strategies and guidelines be

capable of being implemented site-wide and include: the following:

i. Maintaining or restoring core cooling, containment, and SFP cooling capabilities;

and

ii. Enabling the use and receipt of offsite assistance and resources to support the

continued maintenance of the functional capabilities for core cooling, containment, and SFP

cooling indefinitely, or until sufficient site functional capabilities can be maintained without the

need for the mitigation strategies.

130

New reactors may establish different approaches from those of operating reactors in

developing strategies to mitigate beyond-design-basis events. For example, new reactors may

use installed plant equipment for both the initial and long-term response to a loss of all ac power

with less reliance on portable equipment and offsite resources than currently operating nuclear

power plants. The NRC would consider the specific plant approach when evaluating the SSCs

relied on as part of the mitigation strategies for beyond-design-basis events. Additional

information on these strategies is provided in RG 1.226, which endorses an updated version of

the industry guidance, for use by applicants and licensees, that incorporates lessons learned

and feedback stemming from the implementation of the Mitigation Strategies Order, consistent

with Commission direction.

Paragraph 50.155(b)(1) limits the requirements for mitigation strategies to addressing

“external events from natural phenomena.” This language is meant to differentiate these

requirements from those that previously existed in § 50.54(hh)(2) that are now located in

§ 50.155(b)(32), and which address beyond-design-basis external events leading to loss of

large areas of the plant due to explosions and fire.

The requirement to enable “the acquisition and use of offsite assistance and resources

to support the functions required by § 50.155(b)(1)(i) of this section indefinitely, or until sufficient

site functional capabilities can be maintained without the need for the mitigation strategies”

means that licensees need to plan for obtaining sufficient resources (e.g., fuel for generators

and pumps, cooling and makeup water) to continue removing decay heat from the irradiated fuel

in the reactor vessel and SFP as well as to remove heat from containment as necessary until an

alternate means of removing heat is established. The alternate means of removing heat could

be achieved through repairs to existing SSCs, commissioning of new SSCs, or reduction of

decay heat levels through the passage of time sufficient to allow heat removal through losses to

131

the ambient environment. More detailed planning for offsite assistance and resources is

necessary for the initial period following the event; less detailed planning is necessary as the

event progresses and the licensee can mobilize additional support for recovery.

Paragraph 50.155(b)(2) requires licensees who received the March 12, 2012, NRC letter

issued under § 50.54(f) to consider the effects of the reevaluated flooding and seismic hazards

information developed in response to that request, if the magnitude of those hazards exceeds

the external design basis of the licensee’s facility. In § 50.155(b)(2), the phrase, “developed in

response,” is intended to allow licensees the flexibility to rely on NRC-reviewed licensee

adjustments to the hazard calculations originally submitted in response to the § 50.54(f) request.

As discussed further below in this section, the reevaluated hazards are conservative and

bounding, and licensees are provided the flexibility in this final rule to remove conservatism for

their facility to enable more cost-effective means for addressing the information. The words, “if

the magnitude of those hazards,” are intended to convey that it is the magnitude (e.g., flooding

water level) that is being compared to determine which effects to use in developing strategies,

guidelines, or approaches. The current external event design basis of the facility, for the

purposes of § 50.155, is the information on external hazards that was developed during

licensing under GDC 2 or the PDC using guidance and methods that were state-of-the-art at the

time of licensing. Differences may exist between the external design basis for a facility and the

reevaluated flooding and seismic hazard information due to changes in the guidance and

methods used for the determination of conservative values to determine the design basis for

initial siting of a facility.

The words “reevaluated hazard information” are intended to convey that the reevaluated

hazard information is not the design basis for currently operating licensees. The requirement in

GDC 2 results in specific values or ranges of values for controlling parameters as reference

132

bounds for the design in order to establish “design bases” as defined in § 50.2. The methods

used in establishing these values are already intended to be conservative and include sufficient

margin for the limited accuracy, quantity, and period of time in which historical data on the

natural phenomena reported for the site and surrounding area has been accumulated.

Addressing the reevaluated hazard information within the mitigation strategies results in an even

greater capability for addressing external event uncertainty, consistent with the Commission’s

intent for these requirements, and implements the Commission’s direction in

SRM-COMSECY-14-0037.

Recognizing the nature of the reevaluated hazard information, the NRC, through

§ 50.155(b)(2), provides licensees with flexibility in the requirements for addressing the

information. Licensees are required to address the effects of the reevaluated hazard

information using one or both of 1) the mitigation strategies and guidelines of § 50.155(b)(1) as

implemented or modified, and 2) event-specific approaches. As further illustration of the

flexibility provided, RG 1.226 provides acceptable approaches for addressing this information

that includes five different paths that may be used for both flooding and seismic reevaluated

hazard information, including both deterministic and risk-informed approaches. A licensee using

the first approach can show that the mitigation strategies as implemented originally under the

Mitigation Strategies Order or as modified to address the greater magnitude of the reevaluated

hazards are sufficient to address the effects. This approach is similar to the basic approach in

§ 50.155(b)(1). The words “event-specific approaches” mean that a licensee may address the

reevaluated hazard information by considering the damage state that would occur as a

consequence of the hazard scenario. The licensee may then use all available equipment and

SSCs to address that damage state, not necessarily assuming the occurrence of the damage

state of § 50.155(b)(1) of a loss of all ac power and an LUHS if it would not be a consequence

133

of the hazard. For example, for some flooding scenarios, a licensee may be able to estimate

the damage state that the flooding scenario could create at the facility, which enables the

licensee to then identify the equipment available to address the effects of the flooding scenario,

and achieve and maintain a safe shutdown state. It is also possible for the licensee to take

effective pre-emptive measures to place the facility in a safe state for some flood scenarios with

sufficient warning time. The words “event-specific approaches” are intended to provide this

flexibility and do not include the performance elements of § 50.155(b)(1).

Paragraph 50.155(b)(3Paragraph (b)(2) contains the requirements for EDMGs that

previously existed in § 50.54(hh)(2) and are described in the Power Reactor Security

Requirements final rule. The movement of these requirements consolidates the requirements

for beyond-design-basis strategies and guidance into a single section to promote efficiency in

their consideration and allow for better integration. Although the wording of § 50.155(b)(32)

differs from that of previous § 50.54(hh)(2), no substantive change in the requirements is

intended.

The introductory text of § 50.155(b)(32) that is contained in § 50.155(b) is worded so that

it requires that licensees “develop, implement, and maintain” the strategies and guidance

required in § 50.155(b)(32) rather than using the wording of previous § 50.54(hh)(2) to require

that licensees “develop and implement” the described guidance and strategies. The addition of

the word “maintain” is to correct an inconsistency with the wording of § 50.54(hh)(1), which was

issued along with § 50.54(hh)(2) in the Power Reactor Security Requirements final rule. The

requirement as it was originally issued in OrderEAOrder EA-02-026 was worded to require

licensees to “develop” specific guidance, while the corresponding license conditions imposed by

the conforming license amendment was worded to require each affected licensee to “develop

and maintain” strategies. The NRC concludes that the phrase “develop, implement, and

134

maintain” provides better clarity of what is necessary for compliance with the requirements

without substantively changing the requirements.

ParagraphParagraph 50.155(b)(4) requires licensees to integrate the capabilities

required by § 50.155(b) with EOPs. The Commission’s intent regarding integration of

strategies, guidelines, and procedures was introduced in the section-by-section analysis of the

§ 50.155(b) requirement for an integrated response capability and is described further under

“Integration with EOPs” of section V.C of this notice.

Paragraph 50.155(b)(5) requires licensees to provide the staffing necessary for an

integrated response capability to support use of the capabilities in § 50.155(b). The number and

composition of the response staff should be sufficient to implement the capabilities required by

§ 50.155(b). This requirement is not intended to require current licensees, who have performed

staffing analyses to support implementation of the Mitigation Strategies Order or to support

implementation of EDMGs, to redo these staffing analyses. Instead, the staffing requirement is

expected to be verified through the use of drills, existing training analyses and other methods.

The word “sufficient” is used in § 50.155(b)(5) to reflect its meaning: “adequate.”

Paragraph 50.155(b)(6) requires licensees to have a supporting organizational structure

with defined roles, responsibilities, and authorities for directing and performing the capabilities

required by § 50.155(b). This requirement is separate from the requirement in 10 CFR part 50,

appendix E, section IV.A and is intended to support regulatory clarity by providing a clear

demarcation between the command and control requirement implemented under

10 CFR part 50, appendix E and those required for § 50.155. Accordingly, while a licensee may

voluntarily choose to use existing 10 CFR part 50 appendix E plans and implementing

procedures to implement this requirement, that approach is not required by § 50.155(b)(6).

135

Paragraph 50.155(c), “Equipment”

Paragraph 50.155 (c), “Equipment”

Paragraph (c)(1) requires that equipment relied on for the mitigation strategies, and

guidelines, and event-specific approaches of § 50.155(b)(1) and (b)(2) must have sufficient

capacity and capability to perform the functions required by § 50.155(b)(1) and (b)(2).

The phrase “sufficient capacity and capability” in § 50.155(c)(1) means that the

equipment, and the instrumentation relied on to support the decision making necessary to

accomplish the associated mitigation strategies of § 50.155(b)(1) and (b)(2), has the design

specifications necessary to assure that it functions and provides the requisite information on

plant status when subjected to the conditions it is expected to be exposed to in the course of the

execution of those mitigation strategies. These design specifications include appropriate

consideration of environmental conditions that are predicted in the thermal-hydraulic and room

heat up analyses used in the development of the mitigation strategies responsive to

§ 50.155(b)(1) and (b)(2).

Paragraphs 50.155(c)(2) and (c)(3) require reasonable protection of the equipment in

§ 50.155(b)(1) and (b)(2), respectively. Paragraph 50.155(c)(2) requires reasonable protection

of the equipment in § 50.155(b)(1) from the effects of natural phenomemaphenomena that are

equivalent in magnitude to the phenomena assumed for developing the external design basis of

the facility. Paragraph 50.155(c)(3) requires reasonable protection from the effects of the

reevaluated hazards determined in response to the March 12, 2012, NRC letter issued under

§ 50.54(f), but only applies to flooding and seismic reevaluated hazards, and only when those

calculated hazards exceed the external events design basis of the facility. “Reasonable

protection” is the means by which the NRC applies the appropriate level of treatment to

136

equipment and SSCs that are required to function for § 50.155, without regard to whether the

equipment is “FLEX equipment,” as defined in NEI 12-06, or “plant equipment,” as that term is

used in NEI 12-06. Safety-related SSCs that function initially in response to beyond-design-

basis external events have two sets of functions: safety-related functions and beyond-design-

basis functions. The requirements placed on these SSCs to perform their safety-related

functions for the design-basis events are extensive and are intended to result in an increased

level of assurance that the SSCs will perform those safety-related functions, during and/or

following the design-basis events as applicable.

For these dual-function SSCs, the regulatory requirements and resulting level of

regulatory assurance for the beyond-design-basis functions addressed by § 50.155(b)(1) and

(b)(2) for these dual-function SSCs are intended to be less stringent than the requirements

associated with their safety-related functions. The “reasonable protection” requirement is the

means for applying a reduced level of treatment for the beyond-design-basis functions and

establishes an appropriate level of assurance. The phrase “reasonable protection” was initially

proposed in recommendation 4.2 of the NTTF Report in the context of a recommendation for the

NRC to issue an order to licensees to provide “reasonable protection” of equipment required by

the former § 50.54(hh)(2) from the effects of design-basis external events along with providing

additional sets of equipment as an interim measure during a subsequent rulemaking on

prolonged SBO. The NTTF based this recommendation on the potential usefulness of the

EDMGs in circumstances that do not involve the loss of a large area of the plant and explained

that reasonable protection from external events as used in the NTTF Report meant that the

equipment must “be stored in existing locations that are reasonably protected from significant

floods and involve robust structures with enhanced protection from seismic and wind-related

events.”

137

The NRC carried forward the use of the phrase “reasonable protection” in the Mitigation

Strategies Order with regard to the protection required for equipment associated with the

mitigation strategies. That order did not, however, define “reasonable protection.” The NRC

guidance in JLD-ISG-2012-01, Revision 0, discussed “reasonable protection” as follows:

Storage locations chosen for the equipment must provide protection from external events as necessary to allow the equipment to perform its function without loss of capability. In addition, the licensee must provide a means to bring the equipment to the connection point under those conditions in time to initiate the strategy prior to expiration of the estimated capability to maintain core and spent fuel pool cooling and containment functions in the initial response phase. In JLD-ISG-2012-01, Revision 0, the NRC endorsed NEI 12-06, Revision 0, as providing

an acceptable method to provide reasonable protection, storage, and deployment of the

equipment associated with the Mitigation Strategies Order. The NEI 12-06, Revision 0, also

omitted a definition for the phrase “reasonable protection,” but did provide guidelines for use by

licensees for protecting the equipment from the hazards that would be commonly applicable:

1) seismic hazards; 2) flooding hazards; 3) severe storms with high winds; 4) snow, ice and

extreme cold; and 5) high temperatures. Later revisions to the guidance for the Mitigation

Strategies Order included further discussions on reasonable protection. The NEI 12-06,

Revision 2, defined reasonable protection as “[s]toring on-site FLEX equipment in configurations

such that no one external event can reasonably fail the site FLEX capability (N) when the

required FLEX equipment is available.” The JLD-ISG-2012-01, Revision 1, endorsed the

approach of NEI 12-06, Revision 2, as an acceptable method of providing reasonable protection

to the equipment associated with the strategies and guidelines developed under the Mitigation

Strategies Order, clarifying that the elements of the approach that should be addressed are the

following:

- identification of the natural phenomena for which reasonable protection is necessary,

- determination of the method of protection to be used,

138

- establishment of controls on unavailability of the equipment, and

- provision of a method of transporting the portable equipment from its storage location

to the site in which it will be used.

The RG 1.226 carries forward this guidance on reasonable protection, endorsing the

current version of NEI 12-06 as providing an acceptable method of complying with

§ 50.155(c)(2) and (c)(3).

The guidance of RG 1.226 and NEI 12-06 includes the use of structures designed to, or

evaluated as equivalent to, American Society for Civil Engineers Standard 7-10, “Minimum

Design Loads for Buildings and Other Structures,” for the seismic and high winds hazards,

rather than requiring the use of a structure that meets the plant’s design basis for the safe

shutdown earthquake or high winds hazards including missiles. The NEI 12-06 guidelines also

allow storage of the equipment above the flood elevation from the most recent site flood

analysis, storage within a structure designed to protect the equipment from the flood, or storage

below the flood level if sufficient time would be available and plant procedures would address

the need to relocate the equipment above the flood level based on the timing of the limiting flood

scenario(s). The NEI 12-06 guidelines further provide that multiple sets of equipment may be

stored in diverse locations in order to provide assurance that sufficient equipment would remain

deployable to assure the success of the strategies following an initiating event. The

NRC-endorsed guidelines in NEI 12-06 do not consider concurrent, unrelated

beyond-design-basis external events to be within the scope of the initiating events for the

mitigation strategies. There is an assumption of a beyond-design-basis external event that

establishes the event conditions for reasonable protection, and then it is assumed in NEI 12-06

that the event leads to an ELAP and LUHS. There is not, for example, an assumption of

multiple beyond-design-basis external events occurring at the same time. As a result,

139

reasonable protection for the purposes of compliance with § 50.155(c)(2) and (c)(3) allows the

provision of specific sets of equipment for specific hazards with the required protection for those

sets of equipment being against the hazard for which the equipment is intended to be used.

The NRC use of the phrase “reasonable protection” in § 50.155(c)(2) and (c)(3) is

intended to distinguish this approach from the approach of GDC 2 or the PDCs, as

applicableconsistent with GDC 2, which requires that SSCs important to safety be designed to

withstand the effects of natural phenomena. Paragraphs § 50.155(c)(2) and (c)(3) allowallows

damage to, or loss of, specific pieces of equipment so long as the capability to use sufficient

sets of the remaining equipment to accomplish strategies and guidelines is retained.

“Reasonable protection” also allows for protection of the equipment using structures that could

deform as a result of natural phenomena, so long as the equipment could be deployed from the

structure to its place of use.

The remaining portion of § 50.155(c)(2) and (c)(3) sets the hazard level for which

“reasonable protection” of the equipment must be provided. The hazard level is the level

determined for the design basis for the facility for protection of safety-related SSCs from the

effects of natural phenomena under § 50.155(c)(2).

Paragraph 50.155(c)(3) sets the necessary level for the protection for equipment used in

§ 50.155(b)(2) and therefore only applies if the magnitude of the licensee’s reevaluated

hazards, stemming from the March 12, 2012, NRC letter issued under § 50.54(f), exceeds the

hazard level determined for the design basis for the facility. When applicable, § 50.155(c)(3)

sets the level for reasonable protection at the reevaluated hazard levels developed in response

140

to the March 12, 2012, NRC letter, as discussed in the section-by-section analysis of paragraph

(b)(2), above.

Paragraph 50.155(c)(4) requires that each licensee provide sufficient communications

capability, both onsite and offsite, to support implementation of the mitigation strategies and

guidelines of § 50.155(b)(1) and (b)(2). The communications capability requirement is linked

directly to the mitigation strategies requirements in § 50.155(b)(1) and (b)(2) because of the

essential nature of effective communications to successful implementation of the mitigation

strategies and guidelines for beyond-design-basis external events. Accordingly, these

requirements mean that the communication capability must account for the assumed damage

state for § 50.155(b)(1), which is a loss of all ac power concurrent with either an LUHS or, for

passive reactor designs, a loss of normal access to the normal heat sink. Similarly, these

requirements mean that the communication capability must account for the reevaluated hazard

information under § 50.155(b)(2).

In its letter dated March 12, 2012, issued under § 50.54(f), the NRC sought information

from licensees on potential enhancements to support emergency responses to

beyond-design-basis events effecting multiple units at a site. The NRC endorsed NEI 12-01,

“Guideline for Assessing Beyond Design Basis Accident Response Staffing and

Communications Capabilities,” the industry-developed guidance for the responses to this

request, as providing an appropriate method to respond. The NRC assessed licensee

responses regarding communications capabilities and concluded that the need for these

capabilities should be included in the MBDBE rule as a performance-based requirement.

Recognizing that a licensee may modify its approach to complying with the requirements of

§ 50.155 as allowed in § 50.155(g), however, the NRC does not seek to bind licensees to

providing the communications capabilities discussed in their responses to the March 12, 2012,

141

letter, but instead requires under this paragraph that licensees provide sufficient

communications capabilities to accomplish the strategies and guidelines as they exist.

Acceptable approaches for addressing this requirement are provided in RG 1.228, “Integrated

Response Capabilities for Beyond-Design-Basis Events.”

Paragraph 50.155 (d), “Training requirements“

Paragraph 50.155(d) requires that each licensee specified in § 50.155(a) provide for the

training and qualification of licensee personnel that perform activities in accordance with the

capabilities required under § 50.155(b). Paragraph 50.155(d) requires training and qualification

on these activities to be developed using a SAT process as defined in § 55.4. Licensee training

programs, such as those required for licensed operators under 10 CFR part 55, the programs

for plant personnel specified under § 50.120, and the training for emergency response

personnel required by 10 CFR part 50, appendix E, section IV.F, can provide for the knowledge

and abilities required for performing activities described in the strategies and guidelines required

by this final rule. The strategies and guidelines required by the MBDBE rule can use new

methods or equipment that require knowledge and abilities not currently addressed under

existing training programs and, as a result, there can be gaps in these training programs that

must be addressed to support effective use of the strategies and guidelines. Accordingly, the

MBDBE rule requires that licensees provide for the training of personnel using a SAT process,

except for elements already covered under other NRC regulations. The SAT process, which is

acceptable for meeting training requirements under 10 CFR part 55 and § 50.120, is acceptable

for licensee identification and resolution of any current gaps or future modifications to personnel

training that may be necessary to provide for the training of personnel performing activities

under the MBDBE rule. The NRC recognizes that there are other training programs that are

142

currently acceptable for meeting other training required by regulation (e.g., 10 CFR part 50,

appendix E, section IV.F) that do not use the SAT process. In light of the existence of these

training programs, which have been found acceptable for more frequently occurring design-

basis events, the NRC has determined that these training programs can meet the needs for

common elements with beyond-design-basis event mitigation. Therefore, the NRC is not

requiring licensees to revise these training programs to use the SAT process to meet the

MBDBE requirements. Licensees are required to use the SAT process for newly identified

training requirements supporting the effective use of the strategies and guidelines required by

the MBDBE rule.

Paragraph 50.155(e), “Drills or exercises”

Paragraph 50.155(e) requires that each licensee and applicant specified in § 50.155(a)

conduct drills or exercises for personnel that perform activities in accordance with the strategies

and guidelines identified in § 50.155(b)(1) and (3). Under § 50.155(e)(4), this requirement is

extended to include the strategies and guidelines of § 50.155(b)(2), because § 50.155(e)(4)

applies to current operating licensees who received the March 12, 2012, NRC letter issued

under § 50.54(f) and therefore may have mitigation strategies for reevaluated seismic and

flooding hazards. The use of drills or exercises allows demonstration and evaluation of the

licensee’s capability to execute the integrated response capability required by § 50.155(b)

mitigation strategies and guidelines in light of the specific plant damage and operational

conditions presented by an initiating event. The word “integrated” is used to describe the

licensee’s or applicant’s approach to using all tools, spaces, qualified personnel and resources

during a drill or exercise to the extent practical given a set of initiating conditions and within the

bounds of the drill or exercise scenario. When two or more strategies or guidelines in

143

§ 50.155(b)(1) and (3) (or § 50.155(b)(1) through (3) as applicable) are used, “integrated”

means that transitions to and from one set of strategies or guidelines to another are

coordinated.

The drills or exercises conducted by licensees are meant to reasonably simulate the

interactions between the appropriate emergency facilities, teams, and support groups or

individuals that would be expected to occur during the event. For the initial drill or exercise, the

licensee is required to demonstrate its capability to transition to and use one or more of the

strategies that would be required by § 50.155(b)(1) and (3) (or § 50.155(b)(1) through (3) as

applicable) from the AOPs or EOPs, whichever governs for the initiating event and plant

degraded conditions, using the equipment and communication systems used for the EOPs and

guidelines.

Paragraph 50.155(e)(1) requires the initial drill or exercise to be conducted within

12 months prior to the issuance of the first operating license (OL) for the unit described in the

application. This allows the license applicant to implement any improvements or corrective

actions identified during the drill or exercise, and allows the Commission to consider the results

of any drill or exercise actions in the decision on whether to authorize the OL. Because

§ 50.155(e)(1) applies only to applicants for operating licenses, it does not apply to holders of

operating licenses under 10 CFR part 50, who are subject to § 50.155(e)(4), or holders of COLs

under 10 CFR part 52, who are subject to § 50.155(e)(2) through (4). Following issuance of the

operating license, the applicant, as a licensee, is subject to § 50.155(e)(3).

Paragraph 50.155(e)(2) requires the licensee to conduct an initial drill or exercise that

demonstrates the capability to transition from the AOPs or EOPs, using one or more of the

strategies and guidelines in § 50.155(b)(1) and (3) of this section, and demonstrates the

communications capability required by § 50.155(c)(4), no more than 12 months before the date

144

specified for completion of the last inspections, tests, and analyses in the inspections, tests,

analyses, and acceptance criteria (ITAAC) completion schedule as required by § 52.99(a). This

schedule allows the licensee to implement any improvements or corrective actions identified

during the drill or exercise, and allows the Commission to consider the results of any drill or

exercise actions. The schedule is referenced to the ITAAC completion date rather than the date

on which the Commission makes the finding under § 52.103(g) or the initial fuel load in order to

allow licensees to schedule the drill or exercise in advance based on a date certain set by the

licensee. The NRC intends this scheduling requirement to allow licensees to schedule the drill

or exercise efficiently, capturing potential synergies available by combining it with other required

items such as the initial emergency planning exercise.

The § 50.155(e)(2) requirement would apply to any current holders of COLs under

10 CFR part 52 for which the Commission has not yet made the finding under § 52.103(g) as of

the effective date of the MBDBE rule, as well as holders of all future issued COLs. A COL

holder for whom the Commission has already made the finding under § 52.103(g) as of the

effective date of the MBDBE rule is not subject to § 50.155(e)(2), as the schedule referenced to

the ITAAC completion date would already have passed, but instead is subject to § 50.155(e)(4)

for the initial drill requirements.

Paragraph 50.155(e)(3) applies to holders of operating power reactor licenses issued

under 10 CFR part 50 subsequent to the effective date of this final rule, and holders of COLs

issued under 10 CFR part 52 for whom the Commission has made the finding under § 52.103(g)

subsequent to the effective date of this final rule. These licensees would already have

conducted an initial demonstration required by § 50.155 (e)(1) or (e)(2). Paragraph 50.155(e)(3)

provides a continuing requirement to conduct subsequent drills or exercises in succeeding 8-

year intervals to collectively demonstrate a capability to use at least one of the strategies and

145

guidelines in each of § 50.155(b)(1) and (3) (or § 50.155(b)(1) through (3) as applicable). This

requires that the drills or exercises performed to demonstrate this capability include transitions

from other procedures and guidelines, as applicable, and demonstrate the communications

capability required by § 50.155(c)(4). It is structured to require licensees to demonstrate at least

one of the strategies and guidelines from each of the guidelines during the 8-year interval.

Paragraph 50.155(e)(4) requires holders of operating licenses or COLs for which the

Commission has made the finding under § 52.103(g), as of the effective date of the MBDBE

rule, to conduct an initial drill or exercise that demonstrates the capability to transition to and

use one or more of the strategies and guidelines in § 50.155(b)(1) and (3) (or § 50.155(b)(1)

through (3) as applicable) and demonstrate the communications capability required in

§ 50.155(c)(4). Paragraph 50.155(e)(4) is the equivalent to § 50.155(e)(1) and (2) for initial

drills or exercises, but applies to current licensees. Following this initial drill or exercise, the

licensee is required to conduct subsequent drills or exercises in succeeding 8-year intervals to

collectively demonstrate a capability to use at least one of the strategies and guidelines in

§ 50.155(b)(1) or (b)(2), and at least one of the strategies and guidelines in § (b)(3).

Paragraph 50.155(e)(4) is equivalent to § 50.155(e)(3) for subsequent drills or exercises, but

applies to current licensees under 10 CFR part 50 and those under 10 CFR part 52 for whom

the Commission has made the finding under § 52.103(g) as of the effective date of the rule.

Paragraph 50.155(fParagraph (d) requires that each licensee specified in § 50.155(a)

provide for the training of licensee personnel that perform activities in accordance with the

capabilities required under § 50.155(b).

146

Paragraph (e), “Spent fuel pool monitoring”

Paragraph 50.155(f(e) requires each licensee to provide a reliable means to remotely

monitor wide-range water level for each SFP at its site until 5 years have elapsed since all of the

fuel within that SFP was last used in a reactor vessel for power operation. This requirement

enables effective prioritization of event mitigation and recovery actions following

beyond-design-basis external events. This provision does not apply to General Electric Mark III

upper containment pools. These pools are referred to in the UFSARs for the applicable plants,

Clinton Power Station, Grand Gulf Nuclear Station, Perry Nuclear Power Plant, and River Bend

Station, by different terms, such as “upper containment fuel storage pool,” “upper containment

fuel pool,” and “containment upper pool.” The use of the term “upper containment pool” in

§ 50.155(fe) and in this discussion of the paragraph means the pools described in those

UFSARs by those terms. The Mark III upper containment pools are only to store fuel during

refueling outages, at which time the upper pool and reactor coolant system are merged,

mitigating the potential for operator distraction should an extreme event happen at that time.

After refueling is completed, and the reactor is critical, no fuel can be stored in the upper pool,

and instead fuel must either be in the reactor and used to generate power, or it is spent fuel and

stored in the SFP.

Paragraph 50.155(g(f), “Documentation of changes”

Paragraph 50.155(g(f) establishes requirements that govern changes in the

implementation of the requirements of § 50.155. Prior to implementing a change,

§ 50.155(gf)(1) requires the licensee to demonstrate that the provisions of § 50.155 continue to

be met and to maintain documentation of changes until the requirements of § 50.155 no longer

apply. This documentation requirement applies to all changes that impact the implementation of

147

§ 50.155. The NRC recognizes that the licensee will maintain documentation of non-significant

changes as part of their normal procurement and configuration management programs.

Regarding the meaning of demonstrated compliance, changes to the implementation of

§ 50.155 that are consistent with the regulatory guidance supporting the MBDBE rule are

acceptable. Additionally, changes to the implementation of the MBDBE requirements that are

approved alternative approaches, which are shown to apply to the licensee’s facility consistent

with the NRC’s approval, are also acceptable. Changes that are outside of endorsed guidance

or approved alternatives can be demonstrated to comply with § 50.155; however in this regard

the NRC emphasizes that licensees should be mindful of the following context.

1. The NRC initially issued requirements for the mitigation of beyond-design-basis

external events in the Mitigation Strategies Order under the adequate protection

provision of § 50.109(a)(4)(ii). The NRC seeks to ensure through § 50.155(gf) that the

resulting capabilities are maintained. A failure to maintain the functional capabilities first

imposed by the Mitigation Strategies Order and now part of the MBDBE rule would

challenge the continued reasonable assurance of adequate protection of public health

and safety and not equate to demonstrated compliance with § 50.155.

2. The mitigation strategies are intended to address uncertainties associated with

beyond-design-basis external events, and the requirements as implemented provide a

capability that can be used and adapted to any event that exceeds the external design

basis of the facility. While it was necessary for practical reasons to make assumptions

concerning a damage state and conditions that could then be used to provide this

additional capability, it is equally important to preserve the attributes of the mitigation

strategies that provide flexibility, and enable adaptation to unknown events. Significantly

impacting these attributes would reduce the capability for a licensee to successfully

148

apply the strategies to real events. Such a change would not constitute demonstrated

compliance with § 50.155. For example, the mitigation strategies use multiple sets of

equipment, use strategies and guidelines rather than step-by-step procedures, have

contingencies for conditions more severe than the assumed damage state used to

develop the capability, employ alternate connection points, and are supported with

offsite resources to provide for an indefinite capability. All of these are important

elements of the additional mitigation capability for beyond-design-basis external events

required by § 50.155. Changes that result in a significant reduction of these attributes

would result in the mitigation strategies being less flexible and adaptable, and therefore

being less likely to be successfully deployable following a beyond-design-basis external

event. Such changes would not constitute demonstrated compliance. For example,

permanent removal of a set of equipment clearly removes flexibility and lessens the

potential for successful mitigation of a beyond-design-basis external event.

Paragraph 50.155(g(f)(2) requires that changes in the implementation of the

requirements of § 50.155 subject to other change control requirements be processed via their

respective change control processes, unless the changes being evaluated impact only the

implementation of § 50.155. Changes to the implementation of § 50.155 can impact multiple

aspects of the facility. Paragraph 50.155(g(f)(2) is intended to clearly identify that other change

control requirements such as those in §§ 50.59, 50.54(p), 50.54(q), 73.58, and fire protection

change controls may apply depending on the extent of the change and the aspects of the facility

that are impacted. This requirement is not essential because it is the licensee’s obligation to

comply with all applicable regulations; however, given the complexity of facility changes, the

NRC is maintaining this requirement to provide regulatory clarity in the final rule, consistent with

public comment. For example, a change to an SSC having both a beyond-design-basis function

149

for § 50.155 and a design-basis function, would have the aspects of the change involving its

beyond-design-basis functions addressed under § 50.155(gf), and the aspects of the change

involving the design-basis functions addressed under § 50.59 or any other applicable change

control requirement. Another example may be a change to deploy in place equipment for

§ 50.155, that in turn impacts ingress and egress for an area of the facility important for security,

and therefore needs to be evaluated under § 73.58.

Paragraph 50.155(h(g), “Implementation”

Paragraph 50.155(h(g) establishes the compliance schedule for the MBDBE rule.

Paragraph 50.155(h(g)(1) establishes a compliance date of 3 years following the effective date

of the MBDBE rule for each holder of a 10 CFR part 50 operating license who received NRC

Order EA-13-109 and a compliance date of 2 years following the effective date of the MBDBE

rule for each holder of a 10 CFR part 50 operating license that did not receive NRC Order EA-

13-109 and each holder of a 10 CFR part 52 combined license for which the Commission has

made the § 52.103(g) finding as of the effective date of the rule. Paragraph 50.155(h)(2)

provides a flexible schedule provision for currently operating power licensees. For part 50

operating licensees that need additional time beyond the compliance schedule established in

§ 50.155(h)(1), to address the requirements in § 50.155(b)(2), the NRC will consider an

alternative compliance date if the licensee submits to the Director, Office of Nuclear Reactor

Regulation, under § 50.4, no later than 90 days following the effective date of the MBDBE rule,

a schedule request to use § 50.155(h)(2). The request to use § 50.155(h)(2) must provide good

cause for exceeding the 2-year or 3-year compliance date of § 50.155(h)(1). Unless the NRC

notifies a licensee that their request to use § 50.155(h)(2) does not provide good cause, the

request is considered approved by the Commission 120 days after submission.

150

Licensees requesting to use § 50.155(h)(2) may show good cause by supporting their

request with the reasons why compliance with the § 50.155(b)(2) requirement could not be

achieved and a basis for the revised compliance schedule. In addition to the extended

compliance period, a licensee submittal under § 50.155(h)(2) should address portions of the

MBDBE rule for which the licensee is already in compliance. For example, all existing power

reactor licensees were required, under § 50.54(hh)(2), prior to the effective date of the MBDBE

rule, to have the strategies and guidelines now required under § 50.155(b)(3). Continued

compliance with this requirement provides the justification for removal of the Mitigation

Strategies License Conditions. The NRC does not intend to allow a gap in compliance with this

requirement through the use of the flexible scheduling of § 50.155(h)(2). Similarly, the NRC

does not intend to allow a gap in compliance with the requirements of the Mitigation Strategies

Order and those of § 50.155(b)(1). As a result, a licensee proposing a revised compliance

schedule under this provision would need to document in their submittal that they will achieve

compliance with § 50.155(b)(1) prior to the rescission date for the Mitigation Strategies Order to

demonstrate good cause for the revised compliance schedule.

Paragraph 50.155(i), “Rescission(h), “Withdrawal of orders and removal of license conditions”

Under § 50.155(ih)(1), the Mitigation Strategies and SFPI Orders will be

rescindedwithdrawn on [INSERT DATE 3 YEARS AND 30 DAYS AFTER THE EFFECTIVE

DATE OF THE FINAL RULEPUBLICATION].

Under § 50.155(i)(2), Order EA-06-137 will be rescinded on [INSERT THE EFFECTIVE

DATE OF THE FINAL RULE].

151

Under § 50.155(i)(3), on [INSERT THE EFFECTIVE DATE OF THE FINAL RULE], the

Mitigation Strategy License Condition is deemed removed from the power reactor license of

each licensee subject to § 50.155.

Under § 50.155(i)(4), on [INSERT THE EFFECTIVE DATE OF THE FINAL RULE], the

license condition associated with Order EA-06-137 is deemed removed from the power reactor

license of each applicable licensee subject to this section.

Under § 50.155(i)(5h)(2), the reliable SFP/buffer pool level instrumentation, mitigation

strategies for beyond-design-basis external events, and emergency planning license conditions,

except for license condition 2.D(12)(g)1, will be deemed removed from the Enrico Fermi Nuclear

Plant, Unit 3 license on [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE

OF THE FINAL RULEPUBLICATION].

Under § 50.155(i)(6h)(3), the mitigation strategies for beyond-design-basis external

events license condition will be deemed removed from the Virgil C. Summer Nuclear Station,

Units 2 and 3 licenses on [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE

OF THE FINAL RULEPUBLICATION].

Under § 50.155(i)(7h)(4), the mitigation strategies for beyond-design-basis external

events, reliable SFP instrumentation, and emergency planning license conditions, except for

license condition 2.D(12)(j)1, will be deemed removed with the exception of license conditions

2.D(12)(j)1, from the William States Lee III Nuclear Station, Units 1 and 2 licenses on [INSERT

DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE FINAL

RULEPUBLICATION].

Under § 50.155(i)(8h)(5), the reliable SFP/buffer pool level instrumentation, mitigation

strategies for beyond-design-basis external events, and emergency planning license conditions,

except for will be deemed removed with the exception of license condition 2.D(12)(f)1, will be

152

deemed removed from the North Anna Power Station, Unit 3 license on [INSERT DATE 2

YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE RULEPUBLICATION].

Under § 50.155(i)(9h)(6), the mitigation strategies for beyond-design-basis external

events, reliable SFP instrumentation, and emergency planning license conditions, except for will

be deemed removed with the exception of license condition 2.D(12)(h)1, will be deemed

removed from the Turkey Point, Units 6 and 7 licenses on [INSERT DATE 2 YEARS30 DAYS

AFTER THE EFFECTIVE DATE OF THE RULE PUBLICATION].

10 CFR Part 50, Appendix E, Section IV, Training.

This final rule movesmodifies the reference in the § 50.54(hh)(2) exercise requirement

fromwithin 10 CFR part 50, appendix E, section IV.F.2.j, to § 50.155(e). This move changes the

exercise requirementb)(2) to a drill or exercise requirement, aligningreflect the requirement

withmovement of the mitigation strategies drill or exercise requirements described in

§ 50.155(e).EDMG requirement. The final rule also includes administrative changes to use the

numeral “8” rather than the word “eight” in the phrases “8-year” and “8-calendar-year” for

consistency with other sections.

10 CFR Part 50, Appendix E, Section VI, Emergency Response Data Systems.

The NRC is amending its Emergency Response Data Systems regulations to allow the

use of technology-neutral equipment. The requirements in appendix E, section VI,

paragraph 3.c are amended to replace the phrase “onsite modem” with “equipment” and remove

the word “unit.”

153

§ 52.80 Contents of Applications; Additional Technical Information.

Section 52.80 identifies the required additional technical information to be included in an

application for a combined license. Paragraph 52.80(d) is amended to require a combined

license applicant to include the applicant’s plans for implementing the requirements of § 50.155,

including a schedule for achieving full compliance with these requirements. This paragraph

requires the application to include a description of: 1) the integrated response capability

required by § 50.155(b); and 2) the equipment upon which the strategies and guidelines that are

required by § 50.155(b)(1) rely, including the planned locations of the equipment and how the

equipment and SSCs meet the design requirements of § 50.155(c).

VII. Regulatory Flexibility Certification

Under the Regulatory Flexibility Act (5 U.S.C. 605(b)), the NRC certifies that this rule

does not have a significant economic impact on a substantial number of small entities. This rule

affects only the licensing and operation of nuclear power plants. The companies that own these

plants do not fall within the scope of the definition of “small entities” set forth in the Regulatory

Flexibility Act or established in § 2.810, “NRC size standards.”

VIII. Availability of Regulatory Analysis

The NRC has prepared a regulatory analysis on this regulation. The analysis examined

the costs and benefits of the alternatives considered by the NRC. The regulatory analysis is

available as indicated in sectionSection XIX of this noticedocument.

154

IX. Availability of Guidance

The NRC is issuing regulatory guidance for the implementation of the MBDBE rule. The

guidance is available in ADAMS under Accession Nos. ML16301A128, ML16211A166, and

ML16218A236. You may access information and comment submissions related to the guidance

by searching on http://www.regulations.gov under Docket ID NRC-2014-0240. The guidance to

implement the MBDBE rule consists of three RGs, each of which is discussed below.

The RG 1.226 endorses, with clarifications, the methods and procedures in NEI 12-06,

“Diverse and Flexible Coping Strategies (FLEX) Implementation Guide.” This regulatory

guidance provides licensees and applicants with an acceptable method of implementing the

MBDBE rule primarily with regard to the provisions in § 50.155(b)(1), (b)(2), (c), and (gf)

regarding measures for the mitigation of beyond-design-basis external events. Previous

versions of this guidance were endorsed to support compliance with the Mitigation Strategies

Order. Licensees who used previous endorsed versions of NEI 12-06 are not required to revise

their implementation under the Mitigation Strategies Order to address the MBDBE rule

requirements. The later revisions of the endorsed guidance contain additional information for

addressing reevaluated hazard information, frequently asked questions, and acceptable

alternatives, and accordingly provide a larger set of guidance that licensees may use to

implement the MBDBE rule, or to consult when deciding on the acceptability of changes to the

implementation of the MBDBE rule requirements.

The RG 1.227, “Wide-Range Spent Fuel Pool Level Instrumentation,” endorses with

exceptions and clarifications NEI 12-02, Revision 1. This guidance provides an acceptable

method of implementing the MBDBE rule requirement in § 50.155(fe). This RG does not differ

in a significant manner from previously endorsed guidance for the SFPI Order, which was

JLD-ISG-2012-03.

155

The RG 1.228 endorses with clarifications the methods and procedures issued by NEI in

three technical documents:

1. NEI 12-01, Revision 0;

2. NEI 13-06, “Enhancements to Emergency Response Capabilities for Beyond-

Design-Basis Events and Severe Accidents,” Revision 1; and

3. NEI 14-01, “Emergency Response Procedures and Guidelines for Beyond-

Design-Basis Events and Severe Accidents,” Revision 1.

This guidance provides acceptable methods for implementing the MBDBE rule requirements

primarily in § 50.155(b)(4), (b)(5), (d), and (e).d). Changes to the endorsed guidance ensure

consistency with the final rule, but do not contain guidance that substantially differs from that

used previously to support a broad implementation of the Mitigation Strategies and SFPI

Orders.

156

X. Backfitting and Issue Finality

Rule

As required by §§ 50.109 and 52.98, the Commission has completed a backfitting and

issue finality assessment for this rule. The Commission finds that the final rule does not contain

any backfits. Even if change to the staffing and communications types of certifications that COL

holders must submit before the requirements are considered to be backfitting, they are

necessary for licensees to complyof § 50.54(hh)(1) no longer apply is inconsistent with the

MBDBE rule and,issue finality. The change is justified as such, are necessary for adequate

protection of the public health and safety or common defense and security. Thus, the

requirements would satisfy the criteria for an exception from the requirement to conduct a

backfitting analysis under § 50.109(a)(4)(ii). Availability of the backfit and issue finality

assessment is indicated in sectionSection XIX of this noticedocument.

Regulatory Guidance

The NRC is issuing three RGs that provide guidance for the implementation of this rule:

RG 1.226, RG 1.227, and RG 1.228. These RGs provide guidance on the methods acceptable

to the NRC for complying with this final rule. The RGs apply to all current holders of, and

applicants for operating licenses under 10 CFR part 50 and COLs under 10 CFR part 52.

Issuance of the RGs does not constitute backfitting under § 50.109 and does not

otherwise violate issue finality under 10 CFR part 52. As discussed in the “Implementation”

section of each RG, the NRC has no current intention to impose the RGs on current holders of

an operating license or COL.

Applying the RGs to applications for operating licenses or COLs does not constitute

backfitting as defined in § 50.109 and does not otherwise violate issue finality under 10 CFR

157

part 52, because such applicants are not within the scope of entities protected by § 50.109 or

the applicable issue finality provisions in 10 CFR part 52. Neither § 50.109 nor the issue finality

provisions under 10 CFR part 52 – with certain exceptions – were intended to apply to every

NRC action that substantially changes the expectations of current and future applicants.

XI. Cumulative Effects of Regulation

The NRC engaged extensively with external stakeholders throughout this rulemaking

and related regulatory activities. Public involvement has included: 1) issuance of two ANPRs

and two draft regulatory basis documents that requested stakeholder feedback; 2) issuance of

conceptual and preliminary proposed rule language in support of public meetings; 3) numerous

public meetings with the ACRS; 4) issuance of draft final rule language to support meeting with

the ACRS, 5) a public meeting held during the final rule stage to gather additional feedback

concerning CER, and 6) many more public meetings that supported both the development of the

draft regulatory basis documents as well as development of the implementing guidance for the

two orders that this rulemaking makes generically applicable (i.e., the Mitigation Strategies and

SFPI Orders). Section II, “Opportunities for Public Involvement,” of this noticedocument

provides a more detailed discussion of public involvement.

The NRC requested and received feedback following its CER process. The feedback

received is discussed in more detail in conjunction with the consideration of a flexible scheduling

provision, in sectionSection IV of this noticedocument. Most significantly, this final rule includes

a flexible scheduling provision, in § 50.155(h)(2), as well as an additional year for

implementation for licensees that received Order EA-13-109, that is intended to address the

CER feedback received.

158

Regarding the CER process requirements for issuance of guidance, the NRC is issuing

three RGs in conjunction with the issuance of the final rule as discussed in sectionSection IX of

this noticedocument. Additionally the NRC issued draft guidance with the proposed rule for

comment, which enabled more informed external stakeholder feedback to be obtained.

XII. Plain Writing

The Plain Writing Act of 2010 (Pub. L. 111-274) requires Federal agencies to write

documents in a clear, concise, and well-organized manner. The NRC has written this document

to be consistent with the Plain Writing Act as well as the Presidential Memorandum, “Plain

Language in Government Writing,” published June 10, 1998 (63 FR 31883).

XIII. Environmental Assessment and Finding of No Significant Environmental Impact

The Commission has determined under the National Environmental Policy Act of 1969,

as amended, and the Commission’s regulations in subpart A of 10 CFR part 51, that this rule is

not a major Federal action significantly affecting the quality of the human environment, and

therefore an environmental impact statement is not required. The basis of this determination

reads as follows: The action will not result in any radiological effluent impact as it will not

change any design basis structures, systems, or components that function to limit the release of

radiological effluents during or after an accident. This final rule does not change the standards

and requirements for radiological releases and effluents. None of the revisions or additions in

this rule affect current occupational or public radiation exposure. The final rule will not cause

any significant non-radiological impacts, as it will not affect any historic sites or any non-

159

radiological plant effluents. The NRC concludes that this rule will not cause any significant

radiological or non-radiological impacts on the human environment.

The NRC requested the views of the States on the environmental assessment for this

rule. No views were received.

The determination of this environmental assessment is that there will be no significant

effect on the quality of the human environment from this action. The environmental assessment

is available as indicated in sectionSection XIX of this noticedocument.

XIV. Paperwork Reduction Act

This rule contains new or amended information collection requirements that are subject

to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). The collections of

information waswere approved by the Office of Management and Budget, approval number

3150-0011 and 3150-0151.

The burden to the public for the information collection(s) is estimated to average 955

hours per response, including the time for reviewing instructions, searching existing data

sources, gathering and maintaining the data needed, and completing and reviewing the

information collection.

The information collection is being conducted to:

1. Make make changes to existing programs, plans, procedures, and guidelines

implemented as a result of the Mitigating Strategies and SFPI Orders to reflect

the new requirements of this rule, which replaces the order requirements.

2. Support requests to implement the flexible scheduling provisions provided in

§ 50.155(h)(2).

160

3. Support interactions between current operating licensees and the NRC

concerning reevaluated hazard information to support implementation of

§ 50.155(b)(2).

This information will be used by the NRC to support oversight activities associated with

these requirements, to determine whether requests for use of the flexible scheduling provision

have provide good cause for using that provisions, and for making regulatory determinations

regarding the seismic and flooding reevaluated hazard information.. Responses to this

collection of information are mandatory for items 1 and 3 listed above, and voluntary for item 2

listed above.

You may submit comments on any aspect of the information collection(s), including

suggestions for reducing the burden, by the following methods:

• Federal rulemaking Web Sitesite: Go to http://www.regulations.gov and search for

Docket ID <NRC-2014-0240>.

• Mail comments to: FOIA, Privacy, and Information Collections Branch, Office of

Information Services, Mail Stop: T-5 F53, U.S. Nuclear Regulatory Commission,

Washington, DC 20555-0001 or to Vlad Dorjets, Desk Officer, Office of Information

and Regulatory Affairs (3150-AJ49), NEOB-10202, Office of Management and

Budget, Washington, DC 20503; telephone: 202-395-7315, e-mail:

oira_submission@omb.eop.gov.

Public Protection Notification

The NRC may not conduct or sponsor, and a person is not required to respond to, a

collection of information unless the document requesting or requiring the collection displays a

currently valid OMB control number.

161

XV. Congressional Review Act

This final rule is a rule as defined in the Congressional Review Act (5 U.S.C. 801-808).

TheHowever, the Office of Management and Budget has not found it to be a major rule as

defined in the Congressional Review Act.

XVI. Criminal Penalties

For the purposes of Section 223 of the Atomic Energy Act of 1954, as amended (AEA),

the NRC is issuing this rule that amends 10 CFR parts 50 and 52 under one or more of Sections

161b, 161i, or 161o of the AEA. Willful violations of the rule are subject to criminal enforcement.

Criminal penalties as they apply to regulations in 10 CFR parts 50 and 52 are discussed in

§§ 50.111 and 52.303.

162

XVII. Compatibility of Agreement State Regulations

Under the “Policy Statement on Adequacy and Compatibility of Agreement State

Programs,” approved by the Commission on June 20, 1997, and published in the Federal

Register (62 FR 46517; September 3, 1997), this rule is classified as compatibility category

“NRC.” Compatibility is not required for Category “NRC” regulations. The NRC program

elements in this category are those that relate directly to areas of regulation reserved to the

NRC by the AEA or the provisions of Titletitle 10 of the Code of Federal Regulations, and

although an Agreement State may not adopt program elements reserved to the NRC, it may

wish to inform its licensees of certain requirements via a mechanism that is consistent with a

particular State’s administrative procedure laws, but does not confer regulatory authority on the

State.

XVIII. Voluntary Consensus Standards

The National Technology Transfer and Advancement Act of 1995, Public Law 104-113,

requires that Federal agencies use technical standards that are developed or adopted by

voluntary consensus standards bodies unless the use of such a standard is inconsistent with

applicable law or otherwise impractical. In this rule, the NRC is adding requirements for the

mitigation of beyond-design-basis events. This action does not constitute the establishment of a

standard that contains generally applicable requirements.

163

XIX. Availability of Documents

The documents identified in the following table are available to interested persons

through one or more of the following methods, as indicated.

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

Primary Rulemaking Documents Regulatory Analysis ML16301A009 Backfit and Issue Finality Analysis ML16273A010 Environmental Assessment ML16291A188 Information Collection Analysis ML16291A246 Comment Response Document ML16271A063

Regulatory Guides RG 1.226, Flexible Mitigation Strategies for Beyond-Design-Basis Events

ML16301A128

RG 1.227, Wide-Range Spent Fuel Pool Level Instrumentation ML16211A167 RG 1.228, Integrated Response Capabilities for Beyond-Design-Basis Events

ML16218A236

Other References ACRS Transcript—Fukushima Subcommittee, “Discuss Preliminary Mitigation of Beyond-Design-Basis Events Rulemaking Language,” November 21, 2014

ML14337A671

ACRS Transcript—Full Committee, “Discuss Consolidation of Station Blackout Mitigation Strategies and Onsite Emergency Response Capabilities Rulemakings,” July 10, 2014

ML14223A631

ACRS Transcript—Full Committee, “Discuss Preliminary Mitigation of Beyond-Design-Basis Events Rulemaking Language,” December 4, 2014

ML14345A387

ACRS Transcript—Full Committee, “Discuss the Station Blackout Mitigation Strategies Regulatory Basis,” June 5, 2013

ML13175A344

ACRS Transcript—Joint Fukushima and Probabilistic Risk Assessment Subcommittees, “Discuss CPRR Technical Analysis,” August 22, 2014

ML14265A059

ACRS Transcript—Plant Operations and Fire Protection Subcommittee, “Discuss the Onsite Emergency Response Capabilities Regulatory Basis,” February 6, 2013

ML13063A403

ACRS Transcript—Regulatory Policies and Practices Subcommittee, “Discuss the Station Blackout Mitigation Strategies Regulatory Basis,” December 5, 2013, and April 23, 2013

ML13148A404

164

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

ACRS Transcript—Reliability and Probabilistic Risk Assessment Subcommittee, “Discuss CPRR Technical Analysis,” November 19, 2014

ML14337A651

American National Standards Institute/American Nuclear Society 3.2-2012, “Administrative Controls and Quality Assurance for the Operational Phase of Nuclear Power Plants”

http://www.ans.org/store/

American Society for Civil Engineers Standard 7-10, “Minimum Design Loads for Buildings and Other Structures,” 2013

http://www.ascelibrary.org/

“Browns Ferry Nuclear Plant, Units 1, 2, and 3 – Conforming License Amendments To Incorporate the Mitigation Strategies Required by Section B.5.b. of Commission Order EA-02-026 and the Radiological Protection Mitigation Strategies Required by Commission Order EA-06-137,” August 16, 2007

ML072270181

“Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 – Conforming License Amendments To Incorporate the Mitigation Strategies Required by Section B.5.b. of Commission Order EA-02-026,” July 11, 2007

ML071920056

CLI-12-09, “Memorandum and Order,” in the matter of South Carolina Electric & Gas Co. and South Carolina Public Service Authority (also Referred to as Santee Cooper) (Virgil C. Summer Nuclear Station, Units 2 and 3), March 30, 2012

ML12090A531

COMGBJ-11-0002, “NRC Actions Following the Events in Japan,” March 21, 2011

ML110800456

COMSECY-13-0002, “Consolidation of Japan Lessons Learned Near-Term Task Force Recommendations 4 and 7 Regulatory Activities,” January 25, 2013

ML13011A037

COMSECY-13-0010, “Schedule and Plans for Tier 2 Order on Emergency Preparedness for Japan Lessons Learned,” March 27, 2013

ML12339A262

COMSECY-14-0037, “Integration of Mitigating Strategies for Beyond-Design-Basis External Events and The Reevaluation of Flooding Hazards,” November 21, 2014

ML14309A256

“Consolidated Rulemaking – Proof of Concept” (Conceptual Consolidated Preliminary Proposed Rule Language for NTTF Recommendations 4, 7, 8 and 9), February 21, 2014

ML14052A057

“Crystal River Unit 3 – NRC Response to Duke Energy’s Final Response to the March 2012 Request for Information Letter,” January 22, 2014

ML13325A847

“Crystal River Unit 3 Nuclear Generating Plant - Rescission of Order EA-12-049, ‘Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events,’” August 27, 2013

ML13212A366

165

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

“Crystal River Unit 3 – Final Response to March 12, 2012 Information Request Regarding Recommendations 2.1, 2.3 and 9.3,” September 25, 2013

ML13274A341

“Crystal River Unit 3 - Rescission Of Order EA-12-051, ‘Order Modifying Licenses With Regard To Reliable Spent Fuel Pool Instrumentation,’” August 27, 2013

ML13203A161

“Draft Regulatory Basis for Containment Protection and Release Reduction for Mark I and Mark II Boiling Water Reactors (10 CFR Part 50),” May 2015

ML15022A214

Executive Order 13744, “Coordinating Efforts To Prepare the Nation for Space Weather Events,” October 13, 2016

81 FR 71573

Federal Register Notice—Enhancements to Emergency Preparedness Regulations, Final Rule, November 23, 2011

76 FR 72560

Federal Register Notice—Mitigation of Beyond-Design-Basis Events, Proposed Rule, November 13, 2015

80 FR 70609

Federal Register Notice—Mitigation of Beyond-Design-Basis Events, Proposed Rule; correction, November 30, 2015

80 FR 74717

Federal Register Notice—Onsite Emergency Response Capabilities, Advance Notice of Proposed Rulemaking, April 18, 2012

77 FR 23161

Federal Register Notice—Onsite Emergency Response Capabilities, Draft Regulatory Basis, January 8, 2013

78 FR 1154

Federal Register Notice—Onsite Emergency Response Capabilities, Preliminary Proposed Rule Language, November 15, 2013

78 FR 68774

Federal Register Notice—Onsite Emergency Response Capabilities, Regulatory Basis, October 25, 2013

78 FR 63901

Federal Register Notice—Power Reactor Security Requirements, Final Rule, March 27, 2009

74 FR 13926

Federal Register Notice—PRM-50-100, Petition for Rulemaking Submitted by the Natural Resources Defense Council, Inc., July 23, 2013

78 FR 44034

Federal Register Notice—PRM-50-101, Petition for Rulemaking Submitted by the Natural Resources Defense Council, Inc., March 21, 2012

77 FR 16483

Federal Register Notice—PRM-50-102, Petition for Rulemaking; Submitted by the Natural Resources Defense Council, Inc., April 27, 2012

77 FR 25104

Federal Register Notice—PRM-50-96, Long-Term Cooling and Unattended Water Makeup of Spent Fuel Pools, Consideration in the Rulemaking Process, December 18, 2012

77 FR 74788

166

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

Federal Register Notice—PRM-50-97, PRM-50-98, PRM-50-99, PRM-50-100, PRM-50-101, PRM-50-102, Petitions for Rulemaking Submitted by the Natural Resources Defense Council, Inc., Notice of Receipt, September 20, 2011

76 FR 58165

Federal Register Notice—Regulatory Improvements for Decommissioning Power Reactors, Advance Notice of Proposed Rulemaking, November 19, 2015

80 FR 72358

Federal Register Notice—Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors; Final Rule, November 22, 2004

69 FR 68008

Federal Register Notice—Statement of Principles and Policy for the Agreement State Program; Policy Statement on Adequacy and Compatibility of Agreement State Programs, Final Policy Statements, September 3, 1997

62 FR 46517

Federal Register Notice—Station Blackout, Advance Notice of Proposed Rulemaking, March 20, 2012

77 FR 16175

Federal Register Notice—Station Blackout Mitigation Strategies, Draft Regulatory Basis and Draft Rule Concepts, April 10, 2013

78 FR 21275

Federal Register Notice—Station Blackout Mitigation Strategies, Regulatory Basis, July 23, 2013

78 FR 44035

“Fort Calhoun Station, Unit 1 – Rescission of Order EA-12-051, ‘Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation,’” December 8, 2016

ML16320A287

“Fort Calhoun Station, Unit 1 – Relaxation of the Schedule Requirements for Order EA-12-049 ‘Issuance of Order to Modify Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events’ (CAC No. MF0969),” November 21, 2016

ML16277A509

Inspection Manual Chapter (IMC) 0308, “Reactor Oversight Process Basis Document,” Attachment 2, “Technical Basis for Inspection Program,” October 16, 2006

ML062890421

Interim Staff Guidance, NSIR/DPR-ISG-01, “Emergency Planning for Nuclear Power Plants,” November 2011

ML113010523

JLD-ISG-2012-01, “Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” Revision 0, August 29, 2012

ML12229A166

JLD-ISG-2012-01, “Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” Revision 1, January 22, 2016

ML15357A163

167

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

JLD-ISG-2012-01, “Compliance with Order EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” Draft Revision 2, November 4, 2016

ML16277A617

JLD-ISG-2012-03, “Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation,” Revision 0, August 29, 2012

ML12221A339

“Kewaunee Power Station 60-Day Response to March 12, 2012, Information Request Regarding Recommendation 2.1, Seismic Reevaluations,” April 29, 2013

ML13123A004

“Kewaunee Power Station – Rescission of Order EA-12-049, ‘Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events’ (TAC No. MF2774)” June 10, 2014

ML14059A411

“Kewaunee Power Station – Response to Request for Relief from Responding Further to the March 2012 Request for Information Letter for Recommendation 9.3,” January 22, 2014

ML13322B255

Letter from Anne T. Boland, NRC, to J.W. Shea, TVA, “Watts Bar Nuclear Plant, Unit 2 – Request for Tennessee Valley Authority’s Consent to Imposition of New Requirement Related to Mitigation of Beyond-Design-Basis Events,” February 15, 2017

ML17040A353

Letter from Anthony R. Pietrangelo, NEI, to Mark A. Satorius, NRC, “Use of Qualitative Factors in Regulatory Decision Making,” May 11, 2015

ML15217A314

Letter from Eric J. Leeds to Holders of Licenses for Operating Power Reactors as Listed in the Enclosure, “Rescission or Partial Rescission of Certain Power Reactor Security Orders Applicable to Nuclear Power Plants,” November 28, 2011

ML111220447

Letter from J. E. Dyer, NRC, to Holders of Licenses for Operating Power Reactors Listed in the Enclosure, “Order Requiring Compliance with Key Radiological Protection Mitigation Strategies,” August 28, 2006

ML062300304

Letter from John W. Stetkar, ACRS Chairman, to Chairman Stephen G. Burns, NRC, “Draft SECY Paper Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” April 22, 2015

ML15111A271

Letter from J. Sam Armijo, ACRS Chairman, to Mr. R. W. Borchardt, “Response to February 27, 2012 Letter Regarding Final Disposition of Fukushima-Related ACRS Recommendations in Letters Dated October 13, 2011, and November 8, 2011,” March 13, 2012

ML12072A197

168

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

Letter from J.W. Shea to NRC Document Control Desk, “Watts Bar Nuclear Plant, Unit 2 – Response to NRC Request for TVA’s Consent to Imposition of New Requirement Related to Mitigation of Beyond-Design-Basis Events,” March 1, 2017

ML17061A121

Letter from Mark A. Satorius to John W. Stetkar, ACRS, “Draft SECY Paper Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” May 15, 2015

ML15125A485

Letter from Said Abdel-Khalik, ACRS Chairman, to Chairman Gregory B. Jaczko, NRC, “Initial ACRS Review of: (1) the NRC Near-Term Task Force Report on Fukushima and (2) Staff’s Recommended Actions To Be Taken Without Delay,” October 13, 2011

ML11284A136

Memorandum from R. W. Borchardt to J. Sam Armijo, ACRS Chairman, “Final Disposition of the Advisory Committee on Reactor Safeguards’ Review of (1) the U.S. Nuclear Regulatory Commission Near-Term Task Force Report on Fukushima, (2) Staff’s Recommended Actions To Be Taken Without Delay (SECY-11-0124), and (3) Staff’s Prioritization of Recommended Actions To Be Taken in Response to Fukushima Lessons-Learned,” February 27, 2012

ML12030A198

NEI 06-12, “B.5.b Phase 2&3 Submittal Guideline,” Revision 2, December 2006

ML070090060

NEI 10-05, “Assessment of On-Shift Emergency Response Organization Staffing and Capabilities,” Revision 0, June 2011

ML111751698

NEI 12-01, “Guideline for Assessing Beyond Design Basis Accident Response Staffing and Communications Capabilities,” Revision 0, May 2012

ML12125A412

NEI 12-02, “Industry Guidance for Compliance with NRC Order EA-12-051, ‘To Modify License with Regard to Reliable Spent Fuel Pool Instrumentation’,” Revision 1, August 2012

ML122400399

NEI 12-06, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,” Revision 0, August 2012

ML12242A378

NEI 12-06, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,” Revision 1a, October 2015

ML15279A426

NEI 12-06, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,” Revision 2, December 2015

ML15348A015

NEI 12-06, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide,” Revision 3, September 2016

ML16267A274

NEI 13-06, “Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events,” Revision 0, September 2014

ML14269A230

169

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

NEI 13-06, “Enhancements to Emergency Response Capabilities for Beyond Design Basis Accidents and Events,” Revision 1, February 2016

ML16224A618

NEI 14-01, “Emergency Response Procedures and Guidelines for Beyond Design Basis Events and Severe Accidents,” Revision 0, September 2014

ML14269A236

NEI 14-01, “Emergency Response Procedures and Guidelines for Beyond Design Basis Events and Severe Accidents,” Revision 1, February 2016

ML16224A619

NEI 91-04 (formerly NUMARC 91-04), “Severe Accident Issue Closure Guidelines,” Revision 1, December 1994

ML072850981

Non-concurrence NCP-2015-003 ML15091A646 Non-concurrence NCP-2016-018 ML16312A020 NUREG-0654/FEMA-REP-1, “Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants,” Revision 1, November 1980

ML040420012

NUREG-0660, Volume 1 and 2, “NRC Action Plan Developed as a Result of the TMI-2 Accident,” May 1980

ML072470526 and ML072470524

NUREG-0711, “Human Factors Engineering Program Review Model,” Revision 3, November 2012

ML12324A013

NUREG-0737, “Clarification of TMI Action Plan Requirements,” November 1980

ML102560051

NUREG-0737, “Clarification of TMI Action Plan Requirements,” Supplement 1, November 1980

ML102560009

NUREG-0800, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition,” Section 19.4, “Strategies and Guidance To Address Loss-of-Large Areas of the Plant Due to Explosions and Fires,” June 2015

ML13316B202

NUREG-1935, “State-of-the-Art Reactor Consequence Analyses (SOARCA) Report,” November 2012

ML12332A057

“Omaha Public Power District’s Overall Integrated Plan in Response to March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events (Order Number EA-12-049,” February 28, 2013

ML13116A208

Order EA-02-026, “Order for Interim Safeguards and Security Compensatory Measures,” February 25, 2002

ML020510635

Order EA-06-137, “Order Modifying Licenses,” June 20, 2006 ML061600076 Order EA-12-049, “Order Modifying Licenses With Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” (Mitigation Strategies Order), March 12, 2012

ML12054A735

170

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

Order EA-12-051, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation” (SFPI Order), March 12, 2012

ML12056A044

Order EA-12-063, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation” (SFPI Order), March 30, 2012

ML120890218

Order EA-13-109, “Order Modifying Licenses with Regard to Reliable Hardened Containment Vents Capable of Operation under Severe Accident Conditions,” June 6, 2013

ML13130A067

“Preliminary Proposed Rule Language for Mitigation of Beyond-Design-Basis Events Rulemaking,” August 15, 2014

ML14218A253

“Preliminary Proposed Rule Language for Mitigation of Beyond-Design-Basis Events Rulemaking,” made available to the public on November 13, 2014, and December 8, 2014, to support public discussion with the ACRS

ML14336A641

PRM-50-96, “Petition for Rulemaking Submitted by Thomas Popik on Behalf of the Foundation for Resilient Societies To Adopt Regulations that Would Require Facilities Licensed by the NRC under 10 CFR Part 50 To Assure Long-Term Cooling and Unattended Water Makeup of Spent Fuel Pools,” March 14, 2011

ML110750145

PRM-50-98, “NRDC’s Petition for Rulemaking To Require Emergency Preparedness Enhancements for Multiunit Events,” July 26, 2011

ML11216A238

PRM-50-97, “NRDC’s Petition for Rulemaking To Require Emergency Preparedness Enhancements for Prolonged Station Blackouts,” July 26, 2011

ML11216A237

PRM-50-100, “NRDC’s Petition for Rulemaking To Require Licensees to Improve Spent Nuclear Fuel Pool Safety,” July 26, 2014

ML11216A240

PRM-50-101, “NRDC’s Petition for Rulemaking To Revise 10 CFR § 50.63,” July 26, 2011

ML11216A241

PRM-50-102, “NRDC’s Petition for Rulemaking To Require More Realistic Training on Severe Accident Mitigation Guidelines,” July 26, 2011

ML11216A242

Regulatory Issue Summary 2009-13, “Emergency Response Data System Upgrade from Modem to Virtual Private Network Appliance,” September 28, 2009

ML092670124

“Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-Ichi Accident,” March 12, 2012

ML12053A340

171

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

San Onofre Nuclear Generating Station Units 2 and 3, “Final Response to the March 12, 2012 Information Request Regarding Near-Term Task Force Recommendations 2.1, 2.3, and 9.3 and Corresponding Commitments San Onofre Nuclear Generating Station (SONGS) Units 2 and 3,” September 30, 2013

ML13276A020

“San Onofre Nuclear Generating Station, Units 2 and 3, NRC Response to Southern California Edison’s Final Response to the March 2012 Request for Information Letter,” January 22, 2014

ML13329A826

“San Onofre Nuclear Generating Station, Units 2 and 3, Rescission of Order EA-12-049, ‘Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events’ (TAC Nos. MF2657 and MF2658),” June 30, 2014

ML14113A572

“San Onofre Nuclear Generating Station, Units 2 and 3 - Rescission of Order EA-12-051, ‘Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation’ (TAC Nos. MF0917 and MF0918),” June 30, 2014

ML14111A069

SECY-11-0093, “Near-Term Report and Recommendations for Agency Actions Following the Events in Japan,” July 12, 2011

ML11186A950

SECY-11-0124, “Recommended Actions To Be Taken Without Delay from the Near-Term Task Force Report,” September 9, 2011

ML11245A127

SECY-11-0137, “Prioritization of Recommended Actions To Be Taken in Response to Fukushima Lessons Learned,” October 3, 2011

ML11272A111

SECY-12-0025, “Proposed Orders and Requests for Information in Response to Lessons Learned from Japan’s March 11, 2011, Great Tōhoku Earthquake and Tsunami,” February 17, 2012

ML12039A103

SECY-13-0132, “Plan for Updating the U.S. Nuclear Regulatory Commission’s Cost Benefit Guidance,” January 2, 2014

ML13274A495

SECY-14-0046, “Fifth 6-Month Status Update on Response to Lessons Learned from Japan’s March 11, 2011, Great Tōhoku Earthquake and Subsequent Tsunami,” April 17, 2014

ML14064A523

SECY-15-0050, “Cumulative Effects of Regulation Process Enhancements and Risk Prioritization Initiative,” April 1, 2015

ML15034A360

SECY-15-0065, “Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” April 30, 2015

ML15049A201

SECY-15-0085, “Evaluation of the Containment Protection & Release Reduction for Mark I and Mark II Boiling Water Reactors Rulemaking Activities (10 CFR Part 50) (RIN-3150-AJ26),” enclosure entitled, “Containment Protection and Release Reduction (CPRR) Rulemaking: Draft Regulatory Basis,” June 18, 2015

ML15005A079

SECY-16-0142, “Draft Final Rule – Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” December 15, 2016

ML16301A005

172

Document

ADAMS ACCESSION NO. / WEB LINK /

FEDERAL REGISTER CITATION

SECY-89-012, “Staff Plans for Accident Management Regulatory and Research Programs,” January 18, 1989

ML12251A414

SECY-97-132, “Status of the Integration Plan for Closure of Severe Accident Issues and the Status of Severe Accident Research,” June 23, 1997

ML992930144

SECY-98-131, “Status of the Integration Plan for Closure of Severe Accident Issues and the Status of Severe Accident Research,” June 8, 1998

ML992880008

SRM-COMSECY-13-0002, “Consolidation of Japan Lessons Learned Near-Term Task Force Recommendations 4 and 7 Regulatory Activities,” March 4, 2013

ML13063A548

SRM-COMSECY-14-0037, “Integration of Mitigating Strategies for Beyond-Design-Basis External Events and The Reevaluation of Flooding Hazards,” March 30, 2015

ML15089A236

SRM-SECY-11-0093, “Near-Term Report and Recommendations for Agency Actions Following the Events in Japan,” August 19, 2011

ML112310021

SRM-SECY-11-0124, “Recommended Actions To Be Taken Without Delay From the Near-Term Task Force Report,” October 18, 2011

ML112911571

SRM-SECY-11-0137, “Prioritization of Recommended Actions To Be Taken in Response to Fukushima Lessons Learned,” December 15, 2011

ML113490055

SRM-SECY-13-0132, “U.S. Nuclear Regulatory Commission Staff Recommendation for the Disposition of Recommendation 1 of the Near-Term Task Force Report,” May 19, 2014

ML14139A104

SRM-SECY-15-0065, “Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” August 27, 2015

ML15239A767

SRM-SECY-16-0142, “Draft Final Rule – Mitigation of Beyond-Design-Basis Events (RIN 3150-AJ49),” Add date

Add ML No.

Temporary Instruction 2515/191, “Inspection of the Licensee’s Responses to Mitigation Strategies Order EA-12-049, Spent Fuel Pool Instrumentation Order EA-12-051 and Emergency Preparedness Information Requested in NRC March 12, 2012,” March 12, 2012

ML14273A444

“Vermont Yankee Nuclear Power Station – Rescission of Order EA-12-049, ‘Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond Design Basis External Events’ (TAC No. MF4763),” March 2, 2015

ML14321A685

“Vermont Yankee Nuclear Power Station – Rescission of Order EA-12-051, ’Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation’ (TAC No. MF4764),” March 2, 2015

ML14321A696

173

The NRC may post documents related to this rulemaking, including public comments, on

the Federal rulemaking Web site at http://www.regulations.gov under Docket ID

NRC-2014-0240. The Federal rulemaking Web site allows you to receive alerts when changes

or additions occur in a docket folder. To subscribe: 1) navigate to the docket folder

(NRC-2014-0240); 2) click the “Sign up for E-mail Alerts” link; and 3) enter your e-mail address

and select how frequently you would like to receive e-mails (daily, weekly, or monthly).

List of Subjects

10 CFR Part 50

Administrative practice and procedure, Antitrust, Classified information, Criminal

penalties, Education, Fire prevention, Fire protection, Incorporation by reference,

Intergovernmental relations, Nuclear power plants and reactors, Penalties, Radiation protection,

Reactor siting criteria, Reporting and recordkeeping requirements, Whistleblowing.

10 CFR Part 52

Administrative practice and procedure, Antitrust, Backfitting, Combined license, Early

site permit, Emergency planning, Fees, Incorporation by reference, Inspection, Limited work

authorization, Nuclear power plants and reactors, Penalties, Probabilistic risk assessment,

Prototype, Reactor siting criteria, Redress of site, Reporting and recordkeeping requirements,

Standard design, Standard design certification.

For the reasons set out in the preamble and under the authority of the Atomic Energy

Act of 1954, as amended; the Energy Reorganization Act of 1974, as amended; and 5 U.S.C.

552 and 553, the NRC is adopting the following amendments to 10 CFR parts 50 and 52:

174

PART 50 - DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES

1. The authority citation for 10 CFR part 50 continues to read as follows:

Authority: Atomic Energy Act of 1954, secs. 11, 101, 102, 103, 104, 105, 108, 122,

147, 149, 161, 181, 182, 183, 184, 185, 186, 187, 189, 223, 234 (42 U.S.C. 2014, 2131, 2132,

2133, 2134, 2135, 2138, 2152, 2167, 2169, 2201, 2231, 2232, 2233, 2234, 2235, 2236, 2237,

2239, 2273, 2282); Energy Reorganization Act of 1974, secs. 201, 202, 206, 211 (42 U.S.C.

5841, 5842, 5846, 5851); Nuclear Waste Policy Act of 1982, sec. 306 (42 U.S.C. 10226);

National Environmental Policy Act of 1969 (42 U.S.C. 4332); 44 U.S.C. 3504 note; Sec. 109,

Pub. L. 96-295, 94 Stat. 783.

§ 50.8 [Amended]

2. In § 50.8(b), add the number “50.155,” sequentially.

3. In § 50.34, remove the word “stationary” from paragraphs (a)(13) and (b)(12), and

revise paragraph (i) to read as follows:

§ 50.34 Contents of applications; technical information.

* * * * *

(i) Mitigation of beyond-design-basis events. Each application for a power reactor

operating license under this part must include the applicant’s plans for implementing the

175

requirements of § 50.155, including a schedule for achieving full compliance with these

requirements. The application must also include and a description of:

(1) The integrated response capability required by § 50.155(b); and

(2) The the equipment upon which the strategies and guidelines required by

§ 50.155(b)(1) rely, including the planned locations of the equipment and how the equipment

meets the requirements of § 50.155(c).

4. In § 50.54 remove paragraph (hh)(2), redesignate paragraph (hh)(3) as (hh)(2) and

revise it to read as follows:

§ 50.54 Conditions of licenses.

* * * * *

(hh) * * *

(2) Paragraph 50.54(hh)(1) of this section does not apply to a licensee that has

submitted the certifications required under § 50.82(a)(1) or § 52.110(a) of this chapter once the

NRC has docketed those certifications.

* * * * *

5. Add new § 50.155 to read as follows:

§ 50.155 Mitigation of Beyond-Design-Basis Eventsbeyond-design-basis events.

(a) Applicability.

176

(1) Each holder of an operating license for a nuclear power reactor under this part and

each holder of a combined license under part 52 of this chapter for which the Commission has

made the finding under § 52.103(g) of this chapter shall comply with the requirements of this

section until the NRC’s docketingsubmittal of the license holder’s certifications described in

§§§ 50.82(a)(1) or § 52.110(a) of this chapter.

(2)(i) Once the NRC has docketed the certifications described in § 50.82(a)(1) or

§ 52.110(a) of this chapter, have been submitted by a licensee subject to the requirements of

this section, that licensee need only comply with the requirements of § 50.155paragraphs (b)

through (ed), and (gf) of this section associated with spent fuel pool cooling capabilities.

(ii) Holders of operating licenses or combined licenses for which the NRC has docketed

the certifications described in § 50.82(a)(1) or § 52.110(a) of this chapter have been submitted

need not meet the requirements of this section except for the requirements of paragraph (b)(32)

of this section associated with spent fuel pool cooling capabilities once the decay heat of the

fuel in the spent fuel pool can be removed solely by heating and boiling of water within the spent

fuel pool and the boil-off period provides sufficient time for the licensee to obtain off-site

resources to sustain the spent fuel pool cooling function indefinitely, as demonstrated by an

analysis performed and retained by the licensee.

(iii) Dominion Nuclear Connecticut, Inc. (The holder of the license for Millstone Power

Station, Unit 1), is not subject to the requirements of this section.

(iv) Holders of operating licenses or combined licenses for which the NRC has docketed

the certifications described in § 50.82(a)(1) or § 52.110(a) of this chapter have been submitted

need not meet the requirements of this section once all irradiated fuel has been permanently

removed from the spent fuel pool(s).

177

(b) Integrated response capability.(b) Each applicant or licensee shall develop,

implement, and maintain an integrated response capability that includes:

(1) Mitigation Strategiesstrategies for Beyond-Design-Basis External Eventsbeyond-

design-basis external events. Strategies and guidelines to mitigate beyond-design-basis

external events from natural phenomena that are developed assuming a loss of all ac power

concurrent with either a loss of normal access to the ultimate heat sink or, for passive reactor

designs, a loss of normal access to the normal heat sink. These strategies and guidelines must

be capable of being implemented site-wide and must include the following:

(i) Maintaining or restoring core cooling, containment, and spent fuel pool cooling

capabilities; and

(ii) The acquisition and use of offsite assistance and resources to support the functions

required by paragraph (b)(1)(i) of this section indefinitely, or until sufficient site functional

capabilities can be maintained without the need for the mitigation strategies.

(2) Reevaluated Seismic and Flooding Hazards Mitigation. Each licensee that received

the March 12, 2012, NRC letter issued under § 50.54(f) of this part shall consider the effects of

the reevaluated hazards information developed in response to that request if the magnitude of

those hazards exceeds the external design basis of the facility. Licensees shall address the

effects of the reevaluated hazard information using one or both of the following approaches:

(i) The mitigation strategies and guidelines required by paragraph (b)(1) of this section,

as implemented or as modified;

(ii) Event-specific approaches.

(3) Extensive Damage Mitigation Guidelines (EDMGs).(2) Extensive damage mitigation

guidelines (EDMGs). Strategies and guidelines to maintain or restore core cooling, containment,

and spent fuel pool cooling capabilities under the circumstances associated with loss of large

178

areas of the plant impacted by the event, due to explosions or fire, to include strategies and

guidelines in the following areas:

(i) Firefighting;

(ii) Operations to mitigate fuel damage; and

(iii) Actions to minimize radiological release.

(4) Integration of capabilities required by paragraphs (b)(1) through (b)(3) of this section

with the Emergency Operating Procedures (EOPs).

(5) Sufficient staffing to support implementation of the capabilities required in

paragraphs (b)(1) through (b)(3) of this section in conjunction with the EOPs to respond to

events.

(6) A supporting organizational structure with defined roles, responsibilities, and

authorities for directing and performing the capabilities required in paragraphs (b)(1) through

(b)(3) of this section.

(c) Equipment. (1) The equipment relied on for the mitigation strategies, and guidelines,

and event-specific approaches required by paragraphsparagraph (b)(1) and (b)(2) of this section

must have sufficient capacity and capability to perform the functions required by

paragraphsparagraph (b)(1) and (b)(2).

(2) The equipment relied on for the mitigation strategies and guidelines required by

paragraph (b)(1) of this section must be reasonably protected from the effects of natural

phenomena that are equivalent in magnitude to the phenomena assumed for developing the

design basis of the facility.

(3) The equipment relied on for paragraph (b)(2) of this section must be reasonably

protected from the effects of the reevaluated hazards determined in response to the March 12,

2012, NRC letter issued under § 50.54(f) of this part.

179

(4) Each licensee shall provide sufficient communications capability, both onsite and

offsite, to support implementation of the mitigation strategies and guidelines of paragraphs

(b)(1) and (b)(2) of this section.

(d) Training requirements. Each licensee shall provide for the training and qualification

of personnel that perform activities in accordance with the capabilities required by paragraphs

(b)(1) through (b)(3) of this section. The training and qualification on these activities must be

developed using the systems approach to training as defined in § 55.4 of this chapter except for

elements already covered under other NRC regulationsand (b)(2) of this section.

(e) Drills or exercises. (1) An applicant for an operating license issued under this part

shall conduct an initial drill or exercise that demonstrates the capability to transition to and use

one or more of the strategies and guidelines in paragraphs (b)(1) and (b)(3) of this section

including demonstration of the communications capability required by paragraph (c)(4) of this

section, no more than 12 months before issuance of an operating license for the unit described

in the license application.

(2) A holder of a combined license issued under part 52 of this chapter before the

Commission has made the finding under § 52.103(g), shall conduct an initial drill or exercise

that demonstrates the capability to transition to and use one or more of the strategies and

guidelines in paragraphs (b)(1) and (b)(3) of this section including demonstration of the

communications capability required by paragraph (c)(4) of this section, no more than 12 months

before the date specified for completion of the last inspections, tests, and analyses in the

inspections, tests, analyses, and acceptance criteria completion schedule required by

§ 52.99(a) of this chapter for the unit described in the combined license.

(3) Once the Commission issues an operating license to an entity described in

paragraph (e)(1) of this section or makes the finding under § 52.103(g) of this chapter for an

180

entity described in paragraph (e)(2) of this section, the licensee shall conduct subsequent drills

or exercises that collectively demonstrate a capability to use at least one of the strategies and

guidelines in each of paragraphs (b)(1) and (b)(3) of this section in succeeding 8-year intervals.

The drills or exercises performed to demonstrate this capability must include transitions from

other procedures and guidelines as applicable, including demonstration of the communications

capability required by paragraph (c)(4) of this section. Each licensee shall not exceed 8 years

between any consecutive drills or exercises.

(4) A holder of an operating license issued under this part or a combined license under

part 52 of this chapter for which the Commission has made the finding specified in § 52.103(g)

as of [EFFECTIVE DATE OF THE FINAL RULE], shall conduct an initial drill or exercise that

demonstrates the capability to transition to and use one or more of the strategies and guidelines

in paragraphs (b)(1) through (b)(3) of this section, or for a combined license holder paragraphs

(b)(1) and (b)(3), including demonstration of the communications capability required by

paragraph (c)(4) of this section, by [DATE 4 YEARS AFTER EFFECTIVE DATE OF THE

FINAL RULE]. Following this initial drill or exercise, the licensee shall conduct subsequent

drills, exercises, or both that collectively demonstrate a capability to use at least one of the

strategies and guidelines under paragraph (b)(1) or (b)(2), and at least one of the strategies and

guidelines under paragraph (b)(3), or for combined license holders paragraphs (b)(1) and (b)(3)

of this section in succeeding 8-year intervals. The drills or exercises performed to demonstrate

this capability must include transitions from other procedures and guidelines as applicable,

including demonstration of the communications capability required by paragraph (c)(4) of this

section. Each licensee shall not exceed 8 years between any consecutive drills or exercises.

(f(e) Spent fuel pool monitoring. In order to support effective prioritization of event

mitigation and recovery actions, each licensee shall provide reliable means to remotely monitor

181

wide-range water level for each spent fuel pool at its site until 5 years have elapsed since all of

the fuel within that spent fuel pool was last used in a reactor vessel for power generation. This

provision does not apply to General Electric Mark III upper containment pools.

(gf) Documentation of changes. (1) A licensee may make changes in the

implementation of the requirements in this section without NRC approval, provided that before

implementing each such change, the licensee demonstrates that the provisions of this section

continue to be met and maintains documentation of changes until the requirements of this

section no longer apply.

(2) Changes in the implementation of requirements in this section subject to other

change control processes than paragraph (gf) of this section must be processed via their

respective change control processes, unless the changes being evaluated impact only the

implementation of the requirements of this section.

(hg) Implementation. Unless otherwise specified in this section:

(1) Each holder of an operating license for a nuclear power reactor under this part on

[INSERT EFFECTIVE DATE 30 DAYS AFTER THE DATE OF THE FINAL

RULEPUBLICATION] and each holder of a combined license under part 52 of this chapter for

which the Commission made the finding specified in § 52.103(g) as of [INSERT EFFECTIVE

DATE 30 DAYS AFTER THE DATE OF THE FINAL RULEPUBLICATION], shall continue to

comply with the provisions of paragraph (b)(3) of this section, and shall comply with all other

provisions of this section no later than [INSERT DATE 3 YEARS AND 30 DAYS AFTER

EFFECTIVE DATE OF THE FINAL RULEPUBLICATION] for licensees that received NRC

Order EA-13-109 or [INSERT DATE 2 YEARS AND 30 DAYS AFTER EFFECTIVETHE DATE

OF THE FINAL RULEPUBLICATION] for all other applicable licensees.

182

(2) For licensees that cannot achieve compliance with paragraph (b)(2) of this section to

address a reevaluated hazard within the schedule of paragraph (h)(1) of this section, the NRC

will consider an alternative compliance date if the licensee submits to the Director, Office of

Nuclear Reactor Regulation, under § 50.4 of this part, no later than [INSERT DATE 90 DAYS

AFTER THE EFFECTIVE DATE OF THE FINAL RULE], a request to revise the compliance

date with good cause for not achieving compliance within the schedule of paragraph (h)(1) of

this section. Unless the licensee is notified to the contrary, the submitted request to revise the

compliance date will be regarded as approved by the Commission 120 days after submission to

the Commission.

(i) Rescission of orders and removal of license conditions.

(h) Withdrawal of orders and removal of license conditions.

(1) On [INSERT DATE 3 YEARS AND 30 DAYS AFTER EFFECTIVETHE DATE OF

THE FINAL RULEPUBLICATION], Order EA-12-049, “Order Modifying Licenses With Regard

to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” Order EA-

12-051, “Order Modifying Licenses With Regard to Reliable Spent Fuel Pool Instrumentation,”

and Order EA-12-063, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool

Instrumentation,” are rescindedwithdrawn for each licensee or construction permit holder that

was issued those Orders.

(2) On [INSERT THE EFFECTIVE DATE OF THE FINAL RULE], Order EA-06-137,

“Order Modifying Licenses,” is rescinded for each licensee that was issued Order EA-06-137.

(3) On [INSERT THE EFFECTIVE DATE OF THE FINAL RULE], the Mitigation

Strategies License Condition is deemed removed from the power reactor license of each

licensee subject to this section.

183

(4) On [INSERT THE EFFECTIVE DATE OF THE FINAL RULE], the license condition

associated with Order EA-06-137 is deemed removed from the power reactor license of each

applicable licensee subject to this section.

(5) On [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE

FINAL RULEPUBLICATION], Enrico Fermi Nuclear Plant Unit 3, License No. NPF–95, license

conditions 2.D(12)(h), “Reliable Spent Fuel Pool/Buffer Pool Level Instrumentation,” 2.D(12)(i),

“Emergency Planning Actions,” and 2.D(12)(g), “Mitigation Strategies for Beyond-Design-Basis

External Events,” except for 2.D(12)(g)1, are deemed removed from that license.

(63) On [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE

FINAL RULEPUBLICATION], Virgil C. Summer Nuclear Station Unit 2, License No. NPF–93,

license condition 2.D(13), “Mitigation Strategies for Beyond-Design-Basis External Events,” and

Virgil C. Summer Nuclear Station Unit 3, License No. NPF–94, license condition 2.D(13),

“Mitigation Strategies for Beyond-Design-Basis External Events,” are deemed removed from

those licenses.

(7)4) On [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE

FINAL RULEPUBLICATION], William States Lee III Nuclear Station, Unit 1, License No. NPF-

101, license conditions 2.D(12)(d)11 regarding reliable spent fuel pool instrumentation,

2.D(12)(g), “Emergency Planning Actions,” and 2.D(12)(j), “Mitigation Strategies for Beyond-

Design-Basis External Events,” except for 2.D(12)(j)1, and William States Lee III Nuclear

Station, Unit 2, License No. NPF-102, license conditions 2.D(12)(d)11 regarding reliable spent

fuel pool instrumentation, 2.D(12)(g), “Emergency Planning Actions,” and 2.D(12)(j), “Mitigation

Strategies for Beyond-Design-Basis External Events,” except for 2.D(12)(j)1, are deemed

removed from those licenses.

184

(8)5) On [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE

RULEPUBLICATION], North Anna Power Station, Unit 3, License No. NPF-103, license

conditions 2.D(12)(g), “Reliable Spent Fuel Pool/Buffer Pool Level Instrumentation,” 2.D(12)(h),

“Emergency Planning Actions,” and 2.D(12)(f), “Mitigation Strategies for Beyond-Design-Basis

External Events,” except for 2.D(12)(f)1, are deemed removed from the license.

(9)6) On [INSERT DATE 2 YEARS30 DAYS AFTER THE EFFECTIVE DATE OF THE

RULEPUBLICATION], Turkey Point, Unit 6, License No. NPF-104, license conditions

2.D(12)(e)11 regarding reliable spent fuel pool instrumentation, 2.D(12)(g), “Emergency

Planning Actions,” and 2.D(12)(h), “Mitigation Strategies for Beyond-Design-Basis External

Events,” except for 2.D(12)(h)1, and Turkey Point, Unit 7, License No. NPF-105, license

conditions 2.D(12)(e)11 regarding reliable spent fuel pool instrumentation, 2.D(12)(g),

“Emergency Planning Actions,” and 2.D(12)(h), “Mitigation Strategies for Beyond-Design-Basis

External Events,” except for 2.D(12)(h)1, are deemed removed from those licenses.

6. In appendix E to part 50 revise paragraphs IV.F.2.j and VI.3.c to read as follows:

Appendix E to Part 50—Emergency Planning and Preparedness for Production and

Utilization Facilities

* * * * *

IV. * * *

F. * * *

2. * * *

185

j. The exercises conducted under paragraph 2 of this section by nuclear power reactor

licensees must provide the opportunity for the ERO to demonstrate proficiency in the key skills

necessary to implement the principal functional areas of emergency response identified in

paragraph 2.b of this section. Each exercise must provide the opportunity for the ERO to

demonstrate key skills specific to emergency response duties in the control room, TSC, OSC,

EOF, and joint information center. Additionally, in each 8-calendar-year exercise cycle, nuclear

power reactor licensees shall vary the content of scenarios during exercises conducted under

paragraph 2 of this section to provide the opportunity for the ERO to demonstrate proficiency in

the key skills necessary to respond to the following scenario elements: hostile action directed at

the plant site, no radiological release or an unplanned minimal radiological release that does not

require public protective actions, an initial classification of or rapid escalation to a Site Area

Emergency or General Emergency, implementation of strategies, procedures, and guidance

under § 50.155(b)(2), and integration of offsite resources with onsite response. The licensee

shall maintain a record of exercises conducted during each 8-year exercise cycle that

documents the content of scenarios used to comply with the requirements of this paragraph.

Each licensee shall conduct a hostile action exercise for each of its sites no later than

December 31, 2015. The first 8-year exercise cycle for a site will begin in the calendar year in

which the first hostile action exercise is conducted. For a site licensed under 10 CFR part 52,

the first 8-year exercise cycle begins in the calendar year of the initial exercise required by

section IV.F.2.a of this appendix.

* * * * *

VI. * * *

3. * * *

186

c. In the event of a failure of NRC-supplied equipment, a replacement will be furnished

by the NRC for licensee installation.

* * * * *

Part 52 -- LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER

PLANTS

7. The authority citation for part 52 continues to read as follows:

Authority: Atomic Energy Act of 1954, secs. 103, 104, 147, 149, 161, 181, 182, 183,

185, 186, 189, 223, 234 (42 U.S.C. 2133, 2134, 2167, 2169, 2201, 2231, 2232, 2233, 2235,

2236, 2239, 2273, 2282); Energy Reorganization Act of 1974, secs. 201, 202, 206, 211 (42

U.S.C. 5841, 5842, 5846, 5851); 44 U.S.C. 3504 note.

8. In § 52.80, revise paragraph (d) to read as follows:

§ 52.80 Contents of applications; additional technical information.

* * * * *

(d) The applicant’s plans for implementing the requirements of § 50.155 of this chapter

including a schedule for achieving full compliance with these requirements, and a description of:

(1) The integrated response capability required by § 50.155(b) of this chapter; and

(2) The the equipment upon which the strategies and guidelines required by

§ 50.155(b)(1) of this chapter rely, including the planned locations of the equipment and how the

equipment meets the requirements of § 50.155(c) of this chapter.

187

Dated at Rockville, Maryland, this day of , 20172018

For the Nuclear Regulatory Commission.

Annette L. Vietti-Cook, Secretary of the Commission.

KLS Edits

Backfitting and Issue Finality Assessment Supporting the Mitigation of Beyond-Design-Basis Events Final Rule

U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation December 2016

[Insert Date]

1

Mitigation of Beyond-Design-Basis Events Final Rule: Backfitting and Issue Finality

This document provides the U.S. Nuclear Regulatory Commission’s (NRC’s) evaluation of backfitting and issue finality for the final mitigation of beyond-design-basis events (MBDBE) rule. Section 1.0 contains the changes to the backfit analysis in the proposed MBDBE rule stemming from the consideration of public comments on the proposed rule. Section 2.0 describes the MBDBE requirements that make Order EA-12-049, “Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,” (the Mitigation Strategies Order) and Order EA-12-051, “Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation,” (the Spent Fuel Pool Instrumentation (SFPI) Order) generically applicable. These provisions do not constitute backfits and are consistent with issue finality. Section 3.0 provides the NRC’s assessmentevaluation of backfitting and issue finality for anythe remaining change to requirements that areis not a result of making the Mitigation Strategies Order and the SFPI Order generically applicable.

1.0 Changes to the MBDBE Rule Backfitting Assessment As a result of the consideration of public comments provided on the proposed MBDBE rule, the NRC made several changes to improve and clarify it. These changes led to changes for the backfitting justification supporting the MBDBE rule. This section presents an overview of those changes. Removal of Multiple Source Term Dose Assessment Requirements The NRC received public comment concerning the backfitting justification conducted under Title 10 of the Code of Federal Regulations (10 CFR) 50.109, “Backfitting,” for the multiple source term dose assessment requirements that were included in the proposed MBDBE rule. The comment claimed that, while the NRC had correctly identified these requirements as backfits, it had failed to justify their imposition as necessary for adequate protection of public health and safety. Consequently, the NRC had not satisfied 10 CFR 50.109(a)(4)(ii) and was required to prepare a backfit analysis to justify the backfits. The commenter stated that the NRC’s analysis failed to overcome the presumption that compliance with current regulations and orders ensures adequate protection. The commenter quoted from the statement of considerations for the 1988 Backfit Rule: “[T]hat presumption can be overcome only by significant new information or some showing that the regulations do not address some significant safety issue.” The commenter also noted that, beyond the extensive, required actions that licensees are already taking, the industry is voluntarily implementing multiple source term dose assessment capabilities to assist in the mitigation of remote, yet potentially serious, beyond-design-basis external events. The comment stated that the NRC needs to provide a systematic and documented analysis that imposition of the new requirements would result in a cost-justified substantial increase in safety. The NRC agrees that the backfit justification supporting the proposed multiple source term dose assessment requirements was insufficient and has subsequently concluded that the requirements should be removed from the final rule for the reasons stated in Section IV.E of the MBDBE final rule notice.

2

Relocation and Revision toRemoval of Staffing and Communications Requirements The NRC received public comment that the proposed wording for 10 CFR Part 50, Appendix E, Section VII, requirements could be interpreted by future readers that the proposed staffing and communications requirements must be described in the licensee’s emergency plan, notwithstanding the proposed rule language to the contrary. The commenter said that the clarity of these proposed provisions could be improved if they were moved into 10 CFR 50.155. The commenter proposed that these requirements be incorporated into 10 CFR 50.155 as a separate subparagraph. The NRC agrees that relocatingincluding the staffing and communications requirements toin 10 CFR Part 50.155 improves , Appendix E detracted from the clarity. These of the proposed rule. Moreover, the NRC has reexamined the requirements in the final MBDBE rule may constitute backfitsNRC Order EA-12-049, “Order Modifying Licenses With Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events” (Mitigation Strategies Order), for which staffing and arecommunications were addressed below in Section 3.0at the regulatory guidance level without requirements for staffing and communications, and determined that imposition of requirements in this area would constitute backfitting. ConsiderationThe Mitigation Strategies Order did not include a requirement for staffing. Instead, the order included a performance-based requirement for licensees to develop, implement and maintain guidance and strategies to maintain or restore core cooling, containment and spent fuel pool (SFP) cooling capabilities following a beyond-design-basis external event. The order further required that the strategies be capable of mitigating a simultaneous loss of all alternating current (ac) power and a loss of normal access to the ultimate heat sink and have adequate capacity to address challenges to core cooling, containment, and SFP cooling capabilities at all units on a site subject to the order. In order to address these requirements, the nuclear industry proposed regulatory guidance in Nuclear Energy Institute (NEI) document 12-06, Revision 0, which the NRC staff found to provide an acceptable means of achieving compliance with the Mitigation Strategies Order in Japan Lessons-Learned Project Directorate (JLD) Interim Staff Guidance (ISG) document JLD-ISG-2012-01, Revision 0. NEI 12-06 provides criteria for the development and implementation of the mitigation strategies under the Mitigation Strategies Order that includes staffing considerations in section 11.7. In later versions of NEI 12-06, validation guidance has been added to Appendix E of the document, which includes performance of an integrated review to show that resources, which includes personnel, are adequate and not credited more than once for any given time. These versions included Revision 2 and Revision 4, which the NRC staff found to provide acceptable methods of achieving compliance with the Mitigation Strategies Order in JLD-ISG-2012-01, Revisions 1 and 2 respectively. NEI 12-06, Revision 4 is further found to provide an acceptable method of achieving compliance with the MBDBE rule in Regulatory Guide (RG) 1.226, “Flexible Mitigation Strategies for Beyond-Design-Basis Events.” In parallel with the activities under the Mitigation Strategies Order, power reactor licensees performed and submitted an assessment of the staffing that would be needed to accomplish the strategies in response to a request for information under 10 CFR 50.54(f) that the NRC issued on March 12, 2012. The NRC staff reviewed and evaluated the staffing assessments provided by all power reactor licensees and has reviewed and provided a safety evaluation for licensees’ integrated plans for achieving compliance with the Mitigation Strategies Order as they complete their implementation of those plans. Following a licensee’s achieving compliance and the issuance of the NRC staff’s safety evaluation for the mitigation strategies, the NRC staff completes an inspection of that implementation using Temporary Instruction (TI) 2515/191, “Inspection of the Licensee’s Responses to Mitigation Strategies Order EA-12-049, Spent Fuel

3

Pool Instrumentation Order EA-12-051 and Emergency Preparedness Information Requested in NRC March 12, 2012,” which includes the implementation of the staffing plans provided in response to the March 12, 2012 request for information under 10 CFR 50.54(f). The licensees similarly relied upon the regulatory guidance in NEI 12-06 (see, e.g., section 3.2.2.8) and the commitments made in conjunction with communications assessments developed in response to the March 12, 2012 request for information under 10 CFR 50.54(f) to provide the necessary communications between locations on a site during response to a postulated beyond-design-basis external event and between the site and offsite response organizations. The NRC staff similarly reviewed, evaluated and inspected these communications under the Mitigation Strategies Order and TI 2515/191. The requirements imposed by the Mitigation Strategies Order were sufficient to provide reasonable assurance of adequate protection of public health and safety and no new information was developed with regard to staffing and communications that would modify this conclusion. The imposition of requirements for staffing and communications would not result in a substantial increase in the overall protection of public health and safety or the common defense and security. This follows the Commission’s direction in SRM-SECY-11-0124 that “[i]n order to be effective, approaches should be flexible and able to accommodate a diverse range of circumstances and conditions. In consideration of events beyond the design basis, a regulatory approach founded on performance-based requirements will foster development of the most effective and efficient, site-specific mitigation strategies, similar to how the agency approached the approval of licensee response strategies for the ‘loss of large area’ event under its B.5.b program.” As a result, the imposition of requirements for staffing and communications would not meet the provisions of the Backfit Rule and the issue finality provisions of 10 CFR Part 52 and, therefore, the requirements were removed from the final MBDBE Rule. Removal of Reevaluated Hazards withinfrom the Mitigation StrategiesMBDBE Rule The NRC received comments stating that the need for a licensee’s strategies and guidelines to be capable of execution in the context of the reevaluated flooding and seismic hazards should be addressed in 10 CFR 50.155(b), rather than in 10 CFR 50.155(c)(2). The commenters noted that this change would provide greater flexibility regarding how a licensee can address the hazard effects through changes to mitigation strategies and guidelines, to include changes to equipment protection. Additionally, commenters indicated that the regulation should allow for alternative approaches that would not necessarily address the damage state assumed for 10 CFR 50.155(b)(1), nor necessarily assume the same success criteria, and that should also allow for the use of risk-informed approaches. The NRC agrees with this comment and concludes that it would also result in a regulation that is better aligned with the supporting implementation guidance in Regulatory Guide (RG) 1.226, “Flexible Mitigation Strategies for Beyond-Design-Basis Events,” which provides the flexibility the commenters suggested should be in the rule. The NRC concludes that this revision to the final rule is not a backfit, as discussed below in Section 2.0The NRC agrees that inclusion of requirements for reevaluated hazard treatment in 10 CFR 50.155(c)(2) would limit licensee flexibility in addressing the reevaluated hazards. The NRC further reevaluated the inclusion of the proposed requirements for treatment of the reevaluated flooding and seismic hazards in the MBDBE Rule and concluded that doing so would be inappropriate under the Backfit Rule and inconsistent with the issue finality provisions of 10 CFR Part 52. The mitigation strategies under § 50.155(b)(1) originated in the Mitigation Strategies Order and were justified as necessary to provide adequate protection of public health

4

and safety in light of the uncertainties associated with beyond-design-basis external events and the possibility that extreme natural phenomena could challenge the prevention, mitigation, and emergency preparedness defense-in-depth layers. In COMSECY-14-0037, “Integration of Mitigating Strategies for Beyond Design-Basis External Events and The Reevaluaton of Flooding Hazards,” dated November 21, 2014, the NRC staff recognized the interaction between the development and implementation of mitigation strategies for beyond-design-basis external events under the Mitigation Strategies Order and the reevaluation of flooding hazard levels using present-day regulatory guidance and methodologies from flooding evaluations used for early site permits and combined license reviews under NTTF Recommendation 2.1. To resolve this interaction, in COMSECY-14-0037, the staff “ask[ed] the Commission to support the planned approach by affirming that the MBDBE rulemaking needs to require mitigating strategies that are able to address the reevaluated flooding hazards developed in response to the § 50.54(f) letters in order to ensure reasonable assurance of adequate protection of the public health and safety.” In its SRM dated March 30, 2015, “Staff Requirements - Integration of Mitigating Strategies for Beyond Design-Basis External Events and the Reevaluation of Flooding Hazards,” the Commission did not make the affirmation as requested by the staff. Indeed, if the Commission had made such an affirmation, it would have been obliged to address whether there was an imminent threat to public health and safety. The lack of such an analysis either in COMSECY-14-0037 or SRM-COMSECY-14-0037 or elsewhere indicates that the Commission did not conclude that adequate protection of public health and safety necessitates that the mitigation strategies for beyond-design-basis external events be capable of addressing the reevaluated hazard information. Under paragraph (a)(3) of the Backfit Rule, when the exceptions of paragraph (a)(4) of that section do not apply, the NRC may require backfitting of a facility when it determines, based upon an analysis as described in paragraph (c) of that section, that there is a substantial increase in the overall protection of the public health and safety or the common defense and security to be derived from the backfit and that the direct and indirect costs of implementation for that facility are justified in view of the increased protection. To support that analysis, the Commission directed the staff to evaluate potential changes to the guidance for the integrated assessment of the effects of the flooding hazards on operating reactors and to introduce more realism for the purpose of identifying potential safety enhancements for operating reactors. The changes to the regulatory decision-making process directed in the SRM to COMSECY-14-0137 reflected the recognition that the present-day regulatory guidance and methodologies are intended to identify a necessary level of protection from flooding that would meet the principal design criterion of an application for an operating license or combined license corresponding to Criterion 2 of 10 CFR part 50, appendix A, “General Design Criteria for Nuclear Power Plants,” which states that “[s]tructures, systems and components important to safety shall be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, floods, tsunami, and seiches without loss of capability to perform their safety functions. The design bases for these structures, systems and components shall reflect: (1) appropriate consideration of the most severe of the natural phenomena that have been historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and period of time in which the historical data have been accumulated, (2) appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena and (3) the importance of the safety functions to be performed.” Historically, the margin specified in this criterion has been achieved through the incorporation of conservatisms in the analyses used to determine the flooding design bases for power reactors rather than by the use of a minimum margin above the results of the analyses. The existence of these conservatisms was addressed by the Commission in its direction in the SRM to reduce any unnecessary conservatisms and identify any areas with insufficient conservatisms. Adequate protection of

5

public health and safety does not require the operating power reactor licensees to provide protection against natural phenomena protection levels determined under Criterion 2 of appendix A to 10 CFR part 50 in response to the § 50.54(f) letters issued March 12, 2012. The imposition of generic requirements for that level of protection would not result in a substantial increase in public health and safety and any backfitting in this area should be accomplished on an individual plant basis under the provisions of the Backfit rule. The consideration of whether, in light of the reevaluated external hazards analyses, the operating licenses for power reactor licensees should be modified, suspended, or revoked is being accomplished under the NRC efforts associated with the request for information issued under 10 CFR 50.54(f) on March 12, 2012. The generic imposition of requirements to address the reevaluated seismic and flooding hazards would be inappropriate under the Backfit Rule and inconsistent with the issue finality provisions of 10 CFR Part 52, so these provisions from the proposed rule have been removed from the final MBDBE rule. Removal of Integration Requirements In the Proposed MBDBE Rule, the NRC had included a potential requirement for an overarching integrated response capability comprised of the mitigation strategies for beyond-design-basis external events implemented under the Mitigation Strategies Order and the extensive damage mitigation guidelines (EDMGs) from NRC Order EA-02-026, “Interim Safeguards and Security Compensatory Measures,” dated February 25, 2002, as made generically applicable in the former § 50.54(hh)(2). In addition, the proposed requirements included the integration of this capability with the emergency operating procedures (EOPs). The NRC did not include a documented evaluation under paragraph (a)(4) of the Backfit Rule or a backfit analysis under paragraph (c) of the Backfit Rule to support this proposed requirement. In formulating the final MBDBE Rule, the NRC recognized that neither § 50.54(hh)(2) nor the Mitigation Strategies Order included a requirement for integration of the strategies with each other or with the EOPs. Instead, the need for integration was addressed at the regulatory guidance level, more particularly for the Mitigation Strategies Order because it was issued after the EDMGs were already in existence. This guidance can be found in, for example, NEI 12-06, Revision 0, section 11.4. Since the publication of the Proposed MBDBE Rule, all operating power reactor licensees have come into compliance with the Mitigation Strategies Order and most have been inspected under TI 2515/191. In performing these inspections, NRC inspectors have observed the implementation of the integration of the Mitigation Strategies Order’s strategies following this regulatory guidance. This integration is further demonstrated in the validation that was conducted for the mitigation strategies using the regulatory guidance in, for example, NEI 12-06, Revision 2, Appendix E, in order to conform to the regulatory guidance in NEI 12-06, sections 3.2.1.7.6 and 11.4. The requirements imposed by the Mitigation Strategies and the Interim Safeguards and Security Compensatory Measures Orders were sufficient to provide reasonable assurance of adequate protection and no new information was developed with regard to integration that would modify this conclusion. In addition, requirements for integration would not result in a substantial increase in the overall protection of public health and safety. Therefore, imposing requirements for an integrated response capability and integration with the existing emergency operating procedures would not meet the provisions of the Backfit Rule. The final rule has been revised to remove the proposed requirements for an integrated response capability and integration with the existing emergency operating procedures

6

Modification of Training Requirements In the Proposed MBDBE Rule, the NRC had included training requirements that relocates the training requirement from 10 CFR Part 50, Appendix E, Section IV.F.2.j. for the EDMGs and from the Mitigation Strategies Order for the mitigation strategies for beyond-design-basis external events. These requirements included proposed requirements for the qualification of personnel and the use of the systems approach to training (SAT) as defined in 10 CFR 55.4. Similar to the proposed integration requirements, the proposed qualification and SAT requirements were not accompanied by a backfit analysis or documented evaluation developed under the Backfit Rule, but had been addressed in the regulatory guidance for the EDMGs and the Mitigation Strategies Order. The NRC inspected the training programs in 2008 for the EDMGs under TI 2515/171, “Verification of Site Specific Implementation of B.5.b Phase 2 & 3 Mitigating Strategies,” and has been inspecting these training programs on a routine basis under Inspection Procedures 71111.05T, “Fire Protection (Triennial)” and 71111.05XT, “Fire Protection – NFPA 805 (Triennial)” since January 1, 2010. The NRC reviewed and evaluated the licensees’ overall integrated plans, including their training program plans, for the Mitigation Strategies Order, for which all operating power reactor licensees have come into compliance. The NRC has also inspected training plans under the Mitigation Strategies Order for the majority of operating power reactor licensees under TI 2515/191. The requirements imposed by the Orders were sufficient to provide reasonable assurance of adequate protection of public health and safety and no new information was developed with regard to qualification or the systems approach to training that would modify this conclusion. The NRC also considered whether there would be a substantial increase in the overall protection of the public health and safety or the common defense and security that would result from including requirements in the final rule for qualification or the systems approach to training rather than continuing the practice of addressing them in the regulatory guidance as had been done for the orders. While there would be some benefit in the form of clarity as to what had been found acceptable for compliance with the orders being made generically applicable in this rulemaking, the recharacterization of those items from regulatory guidance to requirements would not constitute a substantial increase in the overall protection of the public health and safety or the common defense and security.

A separate requirement for qualification and the systems approach to training is not needed; such a requirement could constrain an existing licensee or an applicant for a new licensee from developing innovative mitigation strategies that do not rely on them. This follows the Commission’s direction in SRM-SECY-11-0124 that “[i]n order to be effective, approaches should be flexible and able to accommodate a diverse range of circumstances and conditions. In consideration of events beyond the design basis, a regulatory approach founded on performance-based requirements will foster development of the most effective and efficient, site-specific mitigation strategies, similar to how the agency approached the approval of licensee response strategies for the ‘loss of large area’ event under its B.5.b program.” The final rule has been revised to remove requirements for qualification and the use of the systems approach to training. Removal of Requirements for Drills or Exercises In the Proposed MBDBE Rule, the NRC included a requirement for the performance of an initial drill or exercise and recurring drills or exercises of the mitigation strategies for beyond-design-

7

basis external events and EDMGs. These requirements represented a movement of the existing requirement for EDMG exercises included in 10 CFR Part 50, Appendix E, Section IV.F.2.j. and the substitution of drills or exercises for the exercise requirement. In addition, similar to the proposed integration, qualification and SAT requirements, this would recharacterize the treatment of drills or exercises from inclusion in the regulatory guidance for the Mitigation Strategies Order to being a requirement. The proposed requirement was not accompanied by a backfit analysis or documented evaluation developed under the Backfit Rule. In formulating the final MBDBE Rule, the NRC has reassessed the need for an drill or exercise requirement in light of the elements included in the regulatory guidance for the Mitigation Strategies Order that would satisfy the intent of the proposed requirement. In the case of the proposed requirement for an initial drill, the NRC recognized that the validation guidance, included in, for example, NEI 12-06, Revision 2, Appendix E, included the performance of scenarios in simulators, in-plant walkthroughs or demonstrations in order to show that a licensee’s operating staff can perform the strategies in the time necessary to meet the conditions of the thermal-hydraulic analysis the strategies are based upon. In addition, the NRC recognized that the regulatory guidance for the Mitigation Strategies Order includes periodic drills at the same 8-year interval that had been included in the potential requirements of the Proposed MBDBE Rule. (See, NEI 12-06, Revisions 0 and 2, Section 11.6.5, and the incorporation by reference of NEI 13-06, Revision 1, into NEI 12-06, Revision 4, Section 11.6.5.) Since the publication of the Proposed MBDBE Rule, all operating power reactor licensees have come into compliance with the Mitigation Strategies Order and the NRC has reviewed and evaluated their training programs. The NRC has completed inspections of the training programs, which includes the drill programs, of a majority of the operating power reactor licensees under TI 2515/191. The requirements imposed by the Mitigation Strategies Order were sufficient to provide reasonable assurance of adequate protection and no new information was developed with regard to drills or exercises that would modify this conclusion. Additionally, imposing a requirement for drills and exercises would not provide a substantial increase in the overall protection of public health and safety. Therefore, the imposition of a requirement for drills or exercises would not meet the provisions of the Backfit Rule. The requirement for drills and exercises has been removed from the final rule. The removal of the EDMGs from the exercise program under 10 CFR Part 50, Appendix E, Section IV.F.2.j. had been based upon their inclusion in the proposed drill or exercise requirement under the MBDBE Rule. Because this requirement has been removed from the final MBDBE Rule, the NRC has retained the EDMGs in the exercise program of 10 CFR Part 50, Appendix E, Section IV.F.2.j, modifying that regulation to reflect the movement of the EDMG requirement to the MBDBE Rule. Removal of the Severe Accident Management Guidelines Discussion The Commission considered a proposed severe accident management guidelines (SAMG) backfit analysis, provided as part of SECY-15-0065, “Proposed Rulemaking: Mitigation of Beyond-Design-Basis Events.” The Commission concluded that the imposition of SAMG requirements was not warranted. Consequently, SAMGs are not requirements in the MBDBE rule and instead continue to be implemented and maintained through a voluntary industry initiative. For more information on that proposal, refer to the proposed rule published in the Federal Register on November 13, 2015 (80 FR 70609).

8

2.0 MBDBE Rule Provisions that Do Not Constitute Backfits The requirements in the MBDBE rule that make the Mitigating Strategies Order and the SFPI Order generically applicable do not qualify as “backfitting,” as that term is defined in 10 CFR 50.109. Appendix B to the regulatory analysis evaluates the costs of these provisions (i.e., the historical cost analysis). This section discusses why these regulatory requirements do not constitute backfits. Because of differences in the application of 10 CFR 50.109 (the Backfit Rule) and the pertinent issue finality provisions in 10 CFR Part 52 to licensees; entities with existing reactor design certifications (DCs); and future applicants for combined licenses (COLs), DCs, manufacturing licenses (MLs), and standard design approvals (SDAs), the NRC addresses each class separately. Generic Applicability of the Mitigation Strategies Order and the SFPI Order to Holders of Operating Licenses, Construction Permits, and Combined Licenses The NRC determined that the requirements in the final MBDBE rule that make generically applicable the requirements in the Mitigation Strategies Order and the SFPI Order—as applied to current power reactor licensees and construction permit holders to whom the Mitigation Strategies Order and the SFPI Order were directed—do not constitute backfitting under 10 CFR 50.109. These requirements have already been imposed by the orders, so the rule requirements cannot meet the definition of “backfitting” in 10 CFR 50.109(a)(1). With regard to the current COL holders, at the time of the issuance of the Mitigation Strategies Order and the SFPI Order on March 12, 2012, only Southern Nuclear Operating Company (for Vogtle Electric Generating Plant, Units 3 and 4 (Vogtle)) was a COL holder. The NRC’s Mitigation Strategies Order constituted a change to the Vogtle COLs that was necessary for adequate protection under 10 CFR 52.98(a) and 50.109(a)(4)(ii). When issuing the SFPI Order for Vogtle, the Commission exempted itself from the backfitting and issue finality requirements. All other new reactor licensees under 10 CFR Part 52—Detroit Edison Company (for Enrico Fermi Nuclear Plant, Unit 3), South Carolina Electric & Gas Company (for Virgil C. Summer Nuclear Station, Units 2 and 3) (Summer), Nuclear Innovation North America LLC, et al. (for South Texas Project, Units 3 and 4), and Duke Energy FloridaCarolinas, LLC (for LevyWilliam States Lee III Nuclear PlantStation, Units 1 and 2), Virginia Electric and Power Company (for North Anna Unit 3) and Florida Power and Light Company (for Turkey Point, Units 6 and 7)—were still under review and had not received their COLs when the orders were issued. These COL holders were issued license conditions that are equivalent to the order requirements, with the exception of Summer, which received Order EA-12-063 for SFPI. The MBDBE rule is making these previously imposed license conditions and order requirements generically applicable, and is removing the license conditions and rescinding the order requirements. For these requirements, the final MBDBE rule is not imposing new requirements inconsistent with issue finality for these COL holders. MBDBE Rule: Reevaluated Hazards The MBDBE rule contains requirements for licensees who received the March 12, 2012, NRC request for information issued under 10 CFR 50.54(f) to consider the effects of the reevaluated hazards information developed in response to that request, if the magnitude of those hazards exceeds the external events design basis of the facility. The MBDBE rule requires licensees to address the effects of the reevaluated hazard information using one or both of the following two approaches:

9

(1) the mitigation strategies and guidelines required by 10 CFR 50.155(b)(1), as implemented or as modified; or

(2) event-specific approaches. As discussed above, these provisions were moved from 10 CFR 50.155(c)(2) in the proposed rule to 10 CFR 50.155(b)(2) in the final rule, in response to public comment, to enable better alignment with supporting guidance and provide greater flexibility for addressing the reevaluated hazard information. The basis for requiring these provisions within the MBDBE rule is provided in COMSECY-14-0037, “Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards,” and its associated staff requirements memorandum (SRM). As discussed in COMSECY-14-0037, the requirements of the Mitigation Strategies Order were imposed in parallel with the agency’s March 12, 2012, request for information on the reevaluation of external hazards. The Mitigation Strategies Order included a requirement for licensees to provide reasonable protection from external events for equipment associated with the required mitigation strategies without specific reference to the necessary level of protection. The appropriate level of protection from external hazards, particularly flooding, was the subject of discussion in the course of NRC-held public meetings leading up to the issuance of the NRC Japan Lessons-Learned Project Directorate Interim Staff Guidance (JLD-ISG)-2012-01, “Compliance with Order EA-12-049, ‘Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events,’” and its endorsement of the industry guidance for the Mitigation Strategies Order, Nuclear Energy Institute (NEI) 12-06, Revision 0, “Diverse and Flexible Coping Strategies (FLEX) Implementation Guide.” Section 6.2.3.1 of NEI 12-06, Revision 0, specifies that the level of protection for flooding should be “the flood elevation from the most recent site flood analysis. The evaluation to determine the elevation for storage should be informed by flood analysis applicable to the site from early site permits, combined license applications, and/or contiguous licensed sites.” The choice of this hazard level was driven by the recognition that, while the flooding hazard reevaluations by holders of operating licenses and construction permits may not be complete in advance of the development and implementation of the mitigation strategies, information available from flood analyses for nearby sites could be taken into account in choosing the appropriate level to avoid the need for rework or modification of the strategies. Many licensees took the former approach, using their best estimates of potential hazard levels and providing additional margin to the current licensing basis. In COMSECY-14-0037, the NRC staff requested that the Commission affirm that (1) licensees for operating nuclear power plants need to address the reevaluated flooding hazards within their mitigation strategies for beyond-design-basis external events, (2) licensees for operating nuclear power plants may need to address some specific flooding scenarios that could significantly damage the power plant site by developing targeted or scenario-specific mitigation strategies, possibly including unconventional measures, to prevent fuel damage in reactor cores or spent fuel pools, and (3) the NRC staff should revise the flooding assessments and integrate the decisionmaking into the development and implementation of mitigation strategies, in accordance with the Mitigation Strategies Order and this rulemaking. These principles reflect the NEI 12-06 reference to the “most recent flood analysis” previously discussed and the documentation by licensees in their overall integrated plans for the mitigation strategies that, at the time of their submittals, “flood and seismic reevaluations pursuant to the 10 CFR 50.54(f)

10

letter of March 12, 2012, are not completed and therefore not assumed in this submittal. As the reevaluations are completed, appropriate issues would be entered into the corrective action system and addressed on a schedule commensurate with other licensing bases changes.” In SRM-COMSECY-14-0037, the Commission approved the first two items (which pertain to the MBDBE rule) recommended by the NRC staff, regarding the need for operating nuclear power plant licensees to address the reevaluated flood hazards within the mitigation strategies and the potential for using targeted or scenario-specific mitigation strategies. The Commission did not approve the third recommendation, but that recommendation is outside the scope of this rulemaking effort. The MBDBE rule reflects this direction. Accordingly, the NRC concludes that the requirements for licensees to address the effects of the reevaluated hazards information are an essential part of the Mitigation Strategies Order requirements to develop, implement, and maintain guidance and strategies to maintain or restore core cooling, containment and spent fuel pool cooling capabilities following a beyond-design-basis external event. Therefore, the incorporation of these requirements within the MBDBE rule does not constitute a new instance of backfitting. Administrative Amendments to Emergency Response Data System Requirements In 10 CFR Part 50, Appendix E, Section VI, the MBDBE rule removes references to the use of modems in order to make the Emergency Response Data System (ERDS) requirements technology neutral. The NRC considers this revision a minor administrative change to make the NRC’s regulatory requirements consistent with a technological initiative that has already been implemented by industry. The subject requirement, for the NRC to supply replacement equipment in the event of failure, remains unchanged. Because this amendment is an administrative change to a requirement applicable to the NRC in the ERDS regulations, it is not subject to the Backfit Rule. Existing Design Certifications The MBDBE rule does not contain new reactor design requirements and, as such, is not applicable to DC applicants. Current and Future Applicants Applicants and potential applicants (for licenses, permits, and regulatory approvals, such as DCs) are not, with certain exceptions, protected by either the Backfit Rule or any issue finality provisions under 10 CFR Part 52. Neither the Backfit Rule nor the issue finality provisions under 10 CFR Part 52—with certain exclusions not applicable here—were intended to apply to every NRC action that substantially changes the expectations of current and future applicants.

3.0 AssessmentEvaluation of MBDBE Rule Provisions that May Constitute Backfits

As a result of the revisions to the MBDBE rule, including the removal of the multiple source term dose assessment requirements from the final MBDBE rule, as discussed above, the requirements in the final MBDBE rule that may constitute backfits are the staffing and communications requirements. In the proposed MBDBE rule, the NRC stated the following:

These proposed [staffing and communications] requirements are based on the NRC’s information requests pursuant to 10 CFR 50.54(f). These regulatory

11

issues are currently being addressed through Order EA-12-049 implementation guidance (i.e., NRC-endorsed guidance in NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, and NEI 12-01, Guideline for Assessing Beyond Design Basis Accident Response Staffing and Communications Capabilities). Although these proposed requirements for staffing and communications stemmed from separate regulatory action, they were necessary for a proper and complete implementation of Order EA-12-049. As discussed in COMSECY-13-0010, “Schedule and Plans for Tier 2 Order on Emergency Preparedness for Japan Lessons Learned,” dated March 27, 2013 (ADAMS Accession No. ML12339A262), the NRC and licensees determined that a complete implementation of a response to a site-wide, beyond-design-basis external event would require sufficient staffing and communications capabilities for both onsite and to offsite that can occur without ac power and recognizing infrastructure damage. As such they are considered to be part of the Order EA-12-049-imposed requirements.

As discussed in the final MBDBE rule Federal Register notice, the NRC relocated and revised the staffing and communications requirements into 10 CFR 50.155. This revision improves clarity, and as a result, the requirements directly link to 10 CFR 50.155(b)(1). This recognizes the importance of staffing and communications to effectively implement the strategies and guidelines for beyond-design-basis external events and results in improved alignment with implementation guidance. MBDBE Rule: Staffing and Communication Capability Requirements The final MBDBE rule includes requirements for staffing (in 10 CFR 50.155(b)) and communications capabilities (in 10 CFR 50.155(c)), but as discussed above in Section 1.0 of this document, no longer contains the requirements for the performance of staffing and communications capability analyses. The revised and relocated communications and staffing capabilities requirements in the final MBDBE rule directly align 10 CFR 50.155 with implementation of the Mitigation Strategies Order. Specifically, successful implementation of the Mitigation Strategies Order requires sufficient staff and sufficient communications capability to successfully mitigate a beyond-design-basis external event that can affect an entire site and adversely impact surrounding telecommunications infrastructure. The NRC used the information obtained from the 10 CFR 50.54(f) responses to support reaching this determination of the regulatory importance of both staffing and communications for currently licensed reactors. Staffing must be sufficient to implement the mitigation strategies for a sitewide, beyond-design-basis external event to be able to simultaneously maintain or restore all the key functions. This staffing must be supported with communications capabilities that are functional in an event involving the loss of all ac to enable the staff implementing the strategies to effectively communicate onsite during and following such an event, and to enable communications to offsite resource centers, under conditions that may involve significant damage to surrounding telecommunications infrastructure, to request assistance and to interact with key offsite authorities. Both staffing and communications have been part of the Mitigation Strategies Order implementation guidance. As a result, in both cases, successful implementation of the Mitigation Strategies Order addresses these MBDBE requirements, such that licensees in compliance with the Mitigation Strategies Order meet the staffing and communications requirements of 10 CFR 50.155. The NRC did not explicitly identify either the staffing or communications capability requirements of the final MBDBE rule in the Mitigation Strategies Order. Nevertheless, they are essential

12

elements of effective mitigation strategies and guidelines (i.e., the staffing and communications capabilities are necessary for compliance with the Mitigation Strategies Order), and licensees have been demonstrating these capabilities to comply with the Mitigation Strategies Order. Therefore, the NRC maintains that the staffing and communications capabilities requirements in the final MBDBE rule are not new requirements or new or different interpretations of requirements.

Even if requiring licensees to have staffing and communications capabilities in the final MBDBE rule had been viewed to constitute backfitting on current 10 CFR Part 50 licensees or violate issue finality for current COL holders, the NRC would have imposed them following its backfitting process. These requirements are necessary for the successful implementation of the Mitigation Strategies Order, which was imposed under the adequate protection exception criterion of 10 CFR 50.109(a)(4)(ii). Therefore, the staffing and communications capabilities requirements are necessary for adequate protection of public health and safety. These requirements would facilitate the development and implementation of the strategies and guidelines required by 10 CFR 50.155(b)(1)-(2). Without sufficient staffing or communications capabilities, a licensee would not be capable of actually executing the strategies and guidelines required by 10 CFR 50.155(b)(1)-(2). Consequently, the staffing and communications capabilities requirements satisfy the adequate protection backfit analysis exception criterion of 10 CFR 50.109(a)(4)(ii) and, as such, permit the violation of issue finality under 10 CFR 52.98(a). The NRC realized during its preparation of the final rule that one change set forth in the final rule would constitute a backfit. In its revisions to the former 10 CFR 50.54(hh)(3), the final rule revises the reference to 10 CFR 52.110(a)(1) to be 10 CFR 52.110(a) to accurately reference the regulation describing the certifications of permanent cessation of operations and permanent removal of fuel from the reactor vessel. For COL holders, a 10 CFR 52.110(a)(1) certification informs the NRC of the date when the licensee permanently ceased or will permanently cease operations, and a 10 CFR 52.110(a)(2) certification informs the NRC of the date when the licensee permanently removed fuel from the reactor vessel. This change was in the MBDBE proposed rule, and the NRC did not receive any comments on it.

Under the former 10 CFR 50.54(hh)(3), COL holders were required to maintain their 10 CFR 50.54(hh)(1) procedures only until the licensee submits the 10 CFR 52.110(a)(1) certification. Revising the sunsetting language to change 10 CFR 52.110(a)(1) to 10 CFR 52.110(a) requires licensees to maintain these procedures until the licensee submits its 10 CFR 52.110(a)(2) certification. Submission of the 10 CFR 52.110(a)(2) certification could occur days, weeks, or months after submitting the 10 CFR 52.110(a)(1) certification. Notwithstanding the amount of time between the submissions of the two certifications, this rule change is a backfit for COL holders.

This imposition is justified as necessary for adequate protection because Order EA-02-026, from which 10 CFR 50.54(hh) derives, was justified as an adequate protection backfit. In issuing that order, the NRC determined that the 10 CFR 50.54(hh)(1) procedures were necessary for adequate protection due to the risk presented by the presence of fuel in the reactor. Because that risk exists until the fuel is removed from the reactor, a licensee’s maintenance of the 10 CFR 50.54(hh)(1) procedures until the licensee submits its 10 CFR 52.110(a)(2) certification stating that fuel has been removed from the reactor, is necessary for adequate protection.